Stainless Steel Bolts Supplier India | SS304 SS316 | Hex Carriage Socket Flange | M3–M20 | DIN ISO ASTM | A2 A4

Stainless Steel Bolts Supplier India — Krishna Industries (KELOR), Ahmedabad

B2B supplier of SS Bolts in all types and grades — SS304 (A2) / SS316 (A4) / Duplex / Nickel Alloy — Hex Head · Carriage · Socket Cap · Socket Thin Head · Socket Low Head · Hex Flange · Hex Lag · T-Bolt — M3 to M20 & 1/8″ to 3/4″ — 6 mm to 200 mm — DIN / ISO / JIS / ASME / ASTM / IS / BSW standards.

MTC on Request · MOQ 50 Nos · GST Invoice (GSTIN: 24AKLPP6499B1ZT) · Pan India Dispatch from Ahmedabad · 2-Hour Quote

A stainless steel bolt (SS bolt) is an externally threaded fastener with a head — used in conjunction with a nut or threaded hole to clamp components together. Unlike a screw, a bolt is designed to pass through clearance holes in both clamped components and be secured by a nut on the opposite side, providing a removable and re-torquable joint. Stainless steel grades — primarily SS304 (A2) and SS316 (A4) — provide corrosion resistance that carbon steel, zinc-plated, or hot-dipped galvanised bolts cannot match in outdoor, marine, chemical, and coastal environments.

Krishna Industries (KELOR), based in Ahmedabad, Gujarat, supplies the complete range of stainless steel bolts — all head types, all standards, all grades — to EPC contractors, structural fabricators, OEM manufacturers, marine fitout contractors, and industrial buyers across India. GST invoice. MOQ 50 Nos. Pan India dispatch.

Bolt vs Screw — Understanding the Distinction

The terms “bolt” and “screw” are used interchangeably in India but have a technically important distinction that affects correct specification:

Feature	Bolt	Screw
Installation	Passes through clearance holes in both components — nut provides clamping on the opposite side	Threads directly into a tapped hole, material, or substrate — no nut needed
Thread engagement	Full thread engagement via nut — more predictable preload and clamping force	Thread in substrate — engagement depth depends on material thickness and hardness
Removal	Remove nut to disassemble — bolt reusable indefinitely	Repeated removal may damage threads in substrate
Load bearing	Higher — bolt + nut combination has defined, engineered joint preload per torque table	Lower — thread in substrate can strip; not suitable for high-load structural joints
Standards	DIN 931 (partial thread), DIN 933 (full thread), ASME B18.2.1	DIN 912 (socket cap), DIN 7982 (self-tapping), ASME B18.3
Key Note	All items on this page are bolts — they all require nuts for assembly	See our SS Screws page for self-tapping, socket, and machine screws

DIN 931 vs DIN 933 — Partial Thread vs Full Thread Hex Bolt

The single most commonly confused specification in hex bolt procurement in India. Wrong specification results in bolts that either don’t fit the joint geometry or don’t provide the required grip length.

Feature	DIN 931 (Partially Threaded)	DIN 933 (Fully Threaded)
Thread Coverage	Threaded for approximately 2× diameter from the tip — plain (unthreaded) shank under the head	Threaded full length from tip to head bearing face
Plain Shank	✅ Present — shank diameter equals bolt nominal diameter	❌ No plain shank — fully threaded end to end
Grip Length	Plain shank provides defined grip length — critical for shear load applications where the shank (not thread) carries shear	Thread runs through the full joint — no defined shear plane in plain shank
Structural Joints	✅ Preferred — plain shank in shear plane is the correct structural bolt design per IS 800, AISC	⚠️ Thread in shear plane — weaker in shear; not preferred for structural connections
Adjustability	Limited — nut position constrained by thread length	✅ Nut can be positioned anywhere along the full length — ideal for adjustable connections and varying grip lengths
Availability	Available from M8 onwards — short lengths not possible	Available from M3 — full range of short lengths including M3×6 to M3×30
Specify For	Structural steel connections, machinery bolting, pipe flange assembly (where grip length must be controlled), standard M8 and above general industrial use	All small bolt sizes (M3–M6), adjustable connections, channel-frame assembly, general non-structural use where full-length threading is an advantage

⚠️ For pressure flanges (ASME B16.5): Do not use hex bolts (DIN 931/933) for ASME pressure flange assembly. ASME B16.5 requires stud bolts (threaded both ends, plain shank centre) per ASME B7/B7M, not hex bolts. See our Stud Bolt & Threaded Rod page for ASME pressure flange stud bolts.

Types of Stainless Steel Bolts — When to Specify Each

Hex Head Bolt (Hex Bolt)

Most Common · DIN 931 / DIN 933

Six-sided hexagonal head — tightened with standard open-end spanner, ring spanner, or socket
The universal general-purpose industrial bolt type
DIN 931: partially threaded (grip shank + threaded end)
DIN 933: fully threaded from head to tip
Available M3 to M20 in SS304 (A2) and SS316 (A4)
Specify for: structural connections, pipe flanges (non-ASME), machinery, general industrial assembly — every application where standard spanner access is available

Carriage Bolt (Round Head Square Neck)

Tamper-Resistant Timber · DIN 603

Domed round head — no drive recess on top; cannot be tightened or loosened from the bolt head side
Square neck under the head locks into a square hole in timber or thin metal — prevents rotation when tightening nut from below
Provides tamper resistance — nut side only access; bolt head is smooth and inaccessible without destroying the substrate
SS316 preferred — carriage bolts are typically used in outdoor and decking applications where corrosion resistance is critical
Specify for: timber decking to steel frame, outdoor furniture, playground equipment, street furniture, marine timber structures, fencing, and any timber joint requiring tamper-resistance from the visible face

Socket Cap Screw / Bolt

High Strength · DIN 912 / ISO 4762

Cylindrical head with internal hexagonal (Allen key) socket drive — high torque transmission, compact head profile
Higher tensile strength than standard hex bolts of the same nominal size — preferred for high-load, compact assemblies
Used where access space is limited — socket head sits in a counterbored recess, flush or below the surface
Standard for machine guards, process equipment, jigs and fixtures, and precision assemblies
Available M3 to M20 in SS304 (A2-70) and SS316 (A4-80)
Property class A4-100 (SS316 high strength) available on request

Socket Thin Head Bolt

Space-Saving · DIN 7984

Socket cap bolt with a reduced head height (approximately 60% of standard DIN 912 head height)
Lower profile allows use in applications where standard socket cap head height would conflict with adjacent components or cover plates
Slightly lower torque capacity than standard DIN 912 due to reduced driver engagement depth
Specify for: electronics housings, thin panel assemblies, sealed equipment enclosures, automotive trim, and precision instruments where vertical clearance is restricted

Socket Low Head Bolt

Ultra Low Profile · DIN 6912

Even lower profile than DIN 7984 thin head — head height approximately 40% of standard DIN 912
Internal hex socket with a larger diameter drive to maintain adequate torque despite the very low head height
Ideal for assemblies with very tight axial clearance
Specify for: precision machinery, electronic enclosures, medical equipment, and optical instrument assemblies where absolute minimum bolt head protrusion is required
Torque capacity lower than standard socket cap — verify load requirements before substituting

Hex Flange Bolt (Hex Washer Head)

No Separate Washer · DIN 6921

Hex head with an integral circular flange (washer face) under the head — eliminates the need for a separate washer
Serrated (toothed) flange variant grips the substrate to resist loosening under vibration
Larger bearing area than standard hex head — distributes clamping load, prevents pull-through in softer or thinner substrates
Specify for: automotive components, sheet metal assemblies, HVAC equipment, structural frames, thin-wall square and rectangular sections — anywhere a separate washer would be impractical or could be lost

Hex Lag Bolt (Lag Screw)

Heavy Timber · DIN 571

Large hex head with coarse, deep wood-screw thread and pointed (gimlet) tip — designed for heavy-duty fastening into timber without a nut
Unlike other bolts on this page, a lag bolt does not require a nut — it threads directly into pre-drilled timber and relies on thread-in-timber pull-out strength
Larger diameter and coarser thread than machine screws — provides much higher pull-out force in timber
SS316 grade required for outdoor, decking, and treated timber applications
Specify for: heavy timber structural connections, decking frame to joist, timber post to concrete anchorage, landscape timber retaining walls, marine timber structures

T-Bolt (Hammer Head Bolt)

Channel Frame · DIN 787

T-shaped head (or hammer head) that inserts into the slot of a strut channel (Unistrut / cable tray / aluminum extrusion profile) and locks when the nut is tightened
Allows infinite adjustment along the channel without disassembly — slide to position, tighten nut
Essential for Unistrut / Superstrut / channel framing systems used in pipe supports, cable tray, HVAC suspension, and solar panel mounting
Must match the channel slot dimensions — standard channel slot is 11 mm or 12 mm wide; T-head must fit
SS316 T-bolts for outdoor and coastal solar mounting, coastal cable trays, marine installations

SS Grade Selection Guide — SS304 vs SS316 vs Duplex

Grade	Designation	Key Property	✅ Specify For	❌ Not For
SS304 (A2)	AISI 304 / DIN 1.4301 / UNS S30400	18% Cr + 8% Ni — general corrosion resistance	Indoor machinery, HVAC, food non-GMP, pharmaceutical non-cleanroom, general engineering, non-coastal structural — most economical SS grade	Marine, coastal outdoor, seawater, ACQ treated timber, chemical with chlorides — pits above ~150 ppm chloride
SS316 (A4)	AISI 316 / DIN 1.4401 / UNS S31600	18% Cr + 10% Ni + 2–3% Mo — chloride pitting resistance	Marine, coastal, offshore, seawater, swimming pool structures, chemical plant, ACQ/CA treated timber, food GMP, pharmaceutical cleanroom	Budget indoor — 20–30% cost premium over SS304
SS316L	AISI 316L / DIN 1.4404 / UNS S31603	Low carbon — improved weld zone corrosion resistance	Welded SS assemblies in corrosive service — pharmaceutical plant, food GMP, chemical process where heat-affected zone corrosion is a concern	Non-welded standard bolting — specify 316 unless the bolt is part of a welded assembly
SS310	AISI 310 / DIN 1.4845	25% Cr + 20% Ni — high-temperature oxidation resistance	Furnace bolting, kiln fixtures, high-temperature structural connections above 600°C	Standard ambient-temperature applications — significant cost premium
Duplex 2205	UNS S32205 / DIN 1.4462	Dual-phase high strength + chloride pitting resistance	Offshore structural bolting, desalination, seawater infrastructure under high tensile load	Standard industrial — over-specified for typical bolt applications
Nickel Alloy	Monel 400 / Alloy 600 / 625	Extreme corrosion — seawater, acids, alkalis	Seawater submerged structural bolts, chemical process acid flanges, offshore splash zone	Standard construction — specify only where SS316 is inadequate

Property Class Guide — A2-70, A4-80, A4-100

ISO 3506 property classes define both the material (A2 = SS304, A4 = SS316) and the mechanical strength of the bolt. Specifying only the material grade without the property class is incomplete — always specify both.

Property Class	Material	Min. Tensile (MPa)	Min. Yield (MPa)	Specify For
A2-70	SS304 (AISI 304)	700	450	Standard general-purpose SS304 bolting — the default specification for most indoor and non-critical applications
A2-80	SS304 (work-hardened)	800	600	Higher-load SS304 applications — structural connections where A2-70 proof load is insufficient
A4-70	SS316 (AISI 316)	700	450	Standard SS316 bolting in corrosive environments where A4-80 strength is not required
A4-80	SS316 (AISI 316)	800	600	Standard high-strength SS316 — the default for marine, chemical, and food GMP bolting requiring both corrosion resistance AND strength
A4-100	SS316 (work-hardened)	1000	800	High-load offshore, structural, and chemical plant applications in SS316 — where both maximum corrosion resistance and maximum strength are required

SS Hex Bolt Dimensions — DIN 933 (Fully Threaded)

Reference dimensions for SS304 and SS316 hex bolts per DIN 933 / ISO 4017. Width across flats (s), head height (k), and standard lengths.

Thread	Pitch (mm)	Width Flats — s (mm)	Head Height — k (mm)	Standard Lengths (mm)
M3	0.50	5.5	2.0	6, 8, 10, 12, 16, 20, 25, 30
M4	0.70	7.0	2.8	8, 10, 12, 16, 20, 25, 30, 35, 40
M5	0.80	8.0	3.5	10, 12, 16, 20, 25, 30, 35, 40, 50
M6	1.00	10.0	4.0	10, 12, 16, 20, 25, 30, 35, 40, 50, 60
M8	1.25	13.0	5.3	16, 20, 25, 30, 35, 40, 50, 60, 70, 80
M10	1.50	17.0	6.4	20, 25, 30, 35, 40, 50, 60, 70, 80, 100
M12	1.75	19.0	7.5	25, 30, 35, 40, 50, 60, 70, 80, 100, 120
M14	2.00	22.0	8.8	30, 35, 40, 50, 60, 70, 80, 100, 120
M16	2.00	24.0	10.0	30, 35, 40, 50, 60, 70, 80, 100, 120, 150
M18	2.50	27.0	11.5	40, 50, 60, 70, 80, 100, 120, 150
M20	2.50	30.0	12.5	40, 50, 60, 70, 80, 100, 120, 150, 200

SS Bolt Tightening Torque — A2-70 & A4-80 Reference Values

Indicative dry (unlubricated) tightening torque values for SS304 A2-70 and SS316 A4-80 hex bolts. Note: Anti-seize lubricant reduces required torque by approximately 25–30% and is strongly recommended to prevent galling in SS-on-SS assemblies. Always use a torque wrench — overtorquing SS bolts causes galling and fracture; undertorquing results in joint loosening.

Thread	A2-70 Torque (Nm) — Dry	A4-80 Torque (Nm) — Dry	With Anti-Seize (approx.)
M4	1.5–2.0	2.0–2.5	1.2–1.7
M5	3.0–4.0	4.0–5.0	2.5–3.5
M6	5.0–7.0	7.0–9.0	4.0–6.0
M8	12–16	16–20	10–14
M10	25–32	32–40	20–28
M12	42–54	55–70	35–48
M14	68–86	88–112	56–76
M16	100–130	132–168	84–115
M20	200–250	260–330	170–220

ℹ️ Critical — SS Bolt Galling Prevention: Stainless steel austenitic grades (SS304, SS316) are highly susceptible to galling (cold welding / thread seizure) when torqued into SS nuts. Always apply anti-seize lubricant (copper, nickel-based, or PTFE paste) to the threads before assembly. Reduce tightening speed — always make the final 2–3 turns with a hand ratchet, not a power tool. If galling occurs (nut seizes before reaching torque), do not force — the bolt and nut will need to be cut off. Consider specifying anti-galling coated bolts for assemblies that will be repeatedly assembled and disassembled.

Standards Available

Standard	Bolt Types Covered	Key Application
DIN 933	Hex bolt fully threaded	Most common general-purpose hex bolt in India
DIN 931	Hex bolt partially threaded	Structural and machinery bolting where plain shank grip length is required
DIN 912 / ISO 4762	Socket cap bolt	Machine guards, process equipment, precision assemblies
DIN 7984	Socket thin head bolt	Space-restricted assemblies needing lower head profile
DIN 6912	Socket low head bolt	Ultra-low-clearance assemblies
DIN 6921	Hex flange bolt	Sheet metal, automotive, HVAC without separate washer
DIN 603	Carriage bolt	Timber structures, outdoor furniture, tamper-resistant joints
DIN 571	Hex lag bolt (lag screw)	Heavy timber structural connections
DIN 787	T-bolt (hammer head)	Channel frame / Unistrut assembly
ASME B18.2.1	Hex bolts (US)	US-standard EPC and export projects — inch sizes
IS 1367	General fasteners	Indian standard for government / PSU procurement

Available Grades

Grade Family	Grades Available	Key Properties	Typical Bolt Application
Austenitic	SS304 (A2), SS305, SS316 (A4), SS316L, SS310, SS321	Non-magnetic, excellent corrosion resistance — the most common SS family for bolts	General industrial, HVAC, food, marine, coastal, chemical plant
Martensitic	SS410, SS416, SS420, SS431	Magnetic, hardest SS grades, moderate corrosion	High-load structural bolts in moderate corrosion; valve body bolting
Ferritic	SS409, SS430, SS439	Magnetic, moderate corrosion, lower cost	Automotive exhaust brackets, moderate environment structural
Duplex	2205 (Austenitic + Ferritic)	High strength + excellent chloride pitting resistance	Offshore structural, desalination, seawater injection plant
Nickel Alloy	Monel 400, Alloy 600, Alloy 625	Extreme corrosion resistance	Seawater submerged structural joints, chemical plant acid flanges

Applications — Where SS Bolts Are Specified

🏗️ Structural & Civil

SS316 hex bolts for outdoor structural steel connections, coastal bridges, jetty structures, and beachfront construction where galvanised bolts would corrode.

🪵 Decking & Timber

SS316 carriage bolts and lag bolts for heavy timber decking, pergola frames, and outdoor timber structures — tamper-resistant and corrosion-proof in treated timber.

⚓ Marine & Offshore

SS316 hex and socket bolts for marine vessel fittings, offshore platform structural connections, jetty deck fittings, and coastal industrial structures in seawater spray.

🔧 Industrial Equipment

SS304 / SS316 socket cap and hex bolts for machine guards, process equipment panels, pump casings, valve bodies, and instrument mounting frames.

⚡ Solar & Renewables

SS316 T-bolts and hex flange bolts for solar panel mounting channel frames — coastal solar installations particularly require SS316 to withstand salt-laden air.

🍽️ Food & Pharma

SS316 socket cap bolts with smooth polished heads for food processing equipment, dairy plant, and pharmaceutical cleanroom assemblies requiring crevice-free surfaces.

🏭 Chemical Plant

SS316 / Duplex hex bolts for piping support structures, equipment skids, and platform grating connections in chemical and petrochemical process plants.

📦 Custom & OEM

Custom lengths, non-standard grades, anti-galling coatings, and proprietary head geometries for OEM assembly and specification-driven industrial projects.

How to Order SS Bolts from KELOR

Share on WhatsApp or Email — include all of the following:
1. Bolt type — Hex / Carriage / Socket Cap / Socket Thin / Socket Low / Hex Flange / Lag / T-Bolt
2. Thread standard — DIN 933 (full) / DIN 931 (partial) / ASME B18.2.1 (specify)
3. Material grade — SS304 / SS316 / SS316L / SS310 / Duplex
4. Property class — A2-70 / A4-80 / A4-100
5. Diameter — M3 to M20 (or imperial 1/8″–3/4″)
6. Length (mm or inches)
7. Quantity (Nos)
8. Nut & washer required? Yes / No (specify grade to match)
9. MTC / test certificate required? Yes / No
10. Delivery location (for freight calculation)

📱 WhatsApp: +91 93135 43530 | 📧 Email: [email protected]

Why Buy SS Bolts from Krishna Industries?

🏭

B2B Industrial Supplier

Dedicated B2B supplier for EPC contractors, structural fabricators, OEMs, and MRO stores. Not a retail outlet. GST invoice on every order.

📄

MTC & Test Certificates

Mill Test Certificate (MTC) available on request for all SS bolt orders. Grade, property class, and standard conformance documented per order.

⚡

2-Hour Quote

WhatsApp complete specification — price, availability, and delivery timeline confirmed within 2 business hours. No lengthy tender process for standard items.

🚚

Pan India Dispatch

Dispatch from Ahmedabad via VRL Logistics, DTDC, and Professional Courier to all major industrial cities across India.

🔩

Complete Fastener Range

One-stop supplier for bolts, nuts, screws, washers, U bolts, threaded rods, wire nails, and industrial valves — combine orders to reduce freight and paperwork.

✅

GSTIN Verified

GSTIN: 24AKLPP6499B1ZT | IEC: AKLPP6499B. All invoices valid for ITC (Input Tax Credit) claims. Registered under GST since 2017.

Get a Quote for SS Bolts — 2-Hour Response

Hex · Carriage · Socket Cap · Hex Flange · Lag · T-Bolt · SS304 · SS316 · Duplex · M3–M20 · DIN ISO ASTM IS · A2-70 A4-80 · GST Invoice · Pan India Dispatch

📱 WhatsApp / Enquire Now

Quick Specification Summary

Parameter	Details
Product	Stainless Steel Bolts — all types
Bolt Types	Hex Head (DIN 933 Full / DIN 931 Partial) · Carriage Bolt · Socket Cap · Socket Thin Head · Socket Low Head · Hex Flange · Hex Lag · T-Bolt
Materials	SS304 (A2), SS305, SS316 (A4), SS316L, SS310, SS321, SS409, SS410, SS430, Duplex 2205, Nickel Alloy (Monel 400 / Alloy 600 / 625)
Thread Range (Metric)	M3 to M20 (coarse pitch standard; fine pitch on request)
Thread Range (Imperial)	1/8″ to 3/4″ (UNC / UNF / BSW)
Length Range	6 mm to 200 mm / 1/4″ to 8″
Property Classes	A2-70, A2-80, A4-70, A4-80, A4-100 per ISO 3506
Standards	DIN 933 / 931 / 912 / 7984 / 6912 / 6921 / 603 / 571 / 787, ISO 4017 / 4014 / 4762, ASME B18.2.1, IS 1367, BSW
MOQ	50 Nos per type per grade per size
HSN Code	73181590 (hex bolts / other bolts and screws)
GST Rate	18% (HSN 7318)
MTC	Available on request
Dispatch	Ahmedabad — Pan India via VRL Logistics, DTDC, Professional Courier
GSTIN	24AKLPP6499B1ZT

Frequently Asked Questions — Stainless Steel Bolts

What is the difference between DIN 931 and DIN 933 hex bolts?

DIN 933 is a fully threaded hex bolt — the thread runs from the tip all the way to the underside of the head, with no plain shank. DIN 931 is a partially threaded hex bolt — the tip is threaded for approximately two times the nominal diameter, but the shank directly under the head is plain (unthreaded), matching the bolt’s nominal diameter. The plain shank in DIN 931 provides a defined grip length and keeps the threaded portion out of the shear plane in structural connections — this is the correct design for load-bearing structural bolting per IS 800 and international structural standards. DIN 933 is specified when fully threaded is required — for example, in short lengths where DIN 931 cannot provide sufficient thread engagement, in adjustable connections where nut position may vary, or for small-diameter bolts (M3–M6) where partially threaded versions are uncommon. If your drawing or BOM says “hex bolt” without specifying DIN 931 or 933, clarify with the designer — the distinction matters for structural applications.

What is the difference between SS304 and SS316 bolts?

SS304 (A2) bolts contain 18% chromium and 8% nickel — they provide good general corrosion resistance for indoor and non-chloride environments including HVAC, food processing (non-GMP), general engineering, and interior structural. SS316 (A4) bolts add 2–3% molybdenum which significantly increases resistance to chloride pitting and crevice corrosion. Specify SS316 bolts for all marine, coastal, seawater, offshore, treated timber (ACQ/CA), swimming pool, chemical plant, food GMP, and pharmaceutical environments. The cost premium for SS316 over SS304 (approximately 20–30%) is consistently recovered through extended service life and elimination of maintenance costs — particularly for outdoor structural applications where corroded SS304 bolts require cutting and replacement.

What is A2-70 and A4-80 — and what do these designations mean for bolts?

These are ISO 3506 property class designations that define both the stainless steel material and the mechanical strength of the bolt. A2 = AISI 304 (SS304); A4 = AISI 316 (SS316). The number after the dash represents minimum tensile strength in units of 10 MPa — so A2-70 means SS304 bolt with 700 MPa minimum tensile, and A4-80 means SS316 bolt with 800 MPa minimum tensile. When a drawing or project specification says “M12 A4-80 hex bolt,” it specifically means an SS316 bolt with 800 MPa tensile — do not substitute A2-70 (SS304) as both the material corrosion resistance and the mechanical property class are different. A4-100 (SS316, 1000 MPa) is also available on request for high-load offshore and chemical plant applications where both maximum corrosion resistance and maximum strength are required.

What is a carriage bolt and when should I use one instead of a hex bolt?

A carriage bolt (DIN 603) has a smooth, domed round head with no drive recess — it cannot be turned from the bolt head side. The square neck under the head locks into a matching square hole in timber or thin metal, preventing rotation when the nut is tightened from the other side. This design provides three important advantages: tamper resistance (anyone can see the bolt head but cannot remove it without access to the nut side), aesthetic cleanliness (smooth dome head is more attractive than a hex head for visible outdoor fixtures), and simplicity (one person can tighten from the nut side without holding the bolt). Specify SS316 carriage bolts for outdoor timber decking to steel frame connections, playground equipment, marine timber structures, street furniture, and any application where the bolt head is visible and exposed to weather or potential tampering. Hex bolts are better where access to both sides is available and you need to apply torque from the bolt head side.

What is a T-bolt and where is it used?

A T-bolt (hammer head bolt, DIN 787) has a T-shaped or rectangular head that is inserted into the longitudinal slot of a strut channel (Unistrut, Superstrut, or equivalent) or aluminium extrusion profile. Once inserted, the T-head is rotated 90° to lock it into the channel slot, and a nut is tightened on the threaded shank to clamp whatever component is being mounted. The key advantage is infinite adjustability — the bolt can slide anywhere along the channel length before being fixed, eliminating the need for precise hole drilling. T-bolts are the standard fastener for channel framing systems used for pipe hangers, cable tray support, HVAC suspension systems, solar panel racking, and equipment skid assembly. Specify SS316 T-bolts for outdoor and coastal applications including coastal solar panel mounting, marine cable trays, and chemical plant pipe support structures where galvanised T-bolts would corrode. The T-bolt head dimensions must match the channel slot — standard channel slot is 11–12 mm wide; confirm the channel manufacturer’s specifications before ordering.

How do I prevent SS bolts from seizing (galling) when tightening?

Thread galling (also called cold welding or seizure) occurs when two SS surfaces (bolt thread and nut thread) slide under high contact pressure — microscopic surface asperities microweld together and the nut seizes before reaching the required torque. Galling is a known problem with austenitic SS304 and SS316 fasteners. Prevention requires one or more of the following: (1) always apply anti-seize lubricant (copper-based paste, nickel-based paste, or PTFE paste) to bolt threads before assembly — this is the single most effective measure; (2) reduce tightening speed — always use a hand ratchet or torque wrench for the final turns, never a power impact driver without speed control; (3) use anti-galling coated bolts — PTFE or molybdenum disulphide dry film coating is applied to the threads at the factory, providing built-in lubrication; (4) for assemblies with repeated assembly/disassembly, specify a dissimilar metal pair (SS316 bolt + Monel nut, for example) to break up the surface affinity that drives galling. Krishna Industries can supply anti-galling coated SS bolts on request — please specify at time of inquiry.

What is the MOQ and lead time for SS bolts?

MOQ is 50 Nos per type per grade per size for standard stock items (SS304 and SS316 hex bolts DIN 933 and socket cap DIN 912 in common metric sizes M6–M16). For non-standard bolt types (carriage, T-bolt, lag), special grades (Duplex, Nickel Alloy), or non-standard lengths, MOQ is 200 Nos with 2–4 weeks lead time. Complete bolt sets (bolt + matching nut + flat washer + spring washer in same SS grade) are available as kits on request. WhatsApp the full specification for confirmed price and availability within 2 hours.