Stud Bolt Price List India 2026 — B7, B8, B16 & L7 Rate Chart by Diameter & Length

1. Stud Bolt Grade Overview & Material Comparison

Stud bolts are fully-threaded fasteners used to secure flanged connections in piping systems, pressure vessels, and structural applications. In the Indian market, four ASTM grades dominate industrial procurement across oil & gas, petrochemical, power generation, and water treatment sectors. Selecting the correct grade depends on operating temperature, corrosion environment, and the flange material specification. The table below summarises each grade’s material composition, typical temperature range, and matching nut specification to help procurement engineers make the right selection before reviewing price data.

2. ASTM A193 B7 Stud Bolt Price Chart — Per Piece (INR)

ASTM A193 B7 stud bolts in alloy steel represent the highest-volume grade in Indian industrial procurement. The prices below reflect standard fully-threaded studs with chamfered ends, supplied with mill test certificates (EN 10204 Type 3.1). Prices vary by diameter and length — larger diameters command a higher per-piece price but offer better value per kilogram due to lower machining overhead per unit weight. B7 studs are typically zinc-plated, black oxide coated, or supplied bare depending on the application environment and customer specification.

The most commonly procured sizes for ASME B16.5 flanges are M16 (5/8″) through M30 (1-1/8″), typically in 150mm to 300mm lengths. For example, a standard 4-inch Class 150 flange requires 8 studs of M20 × 150mm — at the list price above, that is ₹118 per stud or ₹944 for a complete flanged joint’s worth of B7 studs alone (before nuts and gasket). Project buyers ordering 1,000+ sets can negotiate 15–25% below these list rates.

3. ASTM A193 B8 (SS304) Stud Bolt Price Chart — Per Piece (INR)

ASTM A193 B8 stud bolts in SS304 austenitic stainless steel are specified wherever corrosion resistance is required — chemical processing, pharmaceutical, food & beverage, and marine environments. The 80–120% price premium over B7 reflects the significantly higher cost of SS304 raw material (₹180–220/kg versus ₹55–70/kg for alloy steel rod). B8 studs must receive carbide solution treatment per ASTM A193, adding to the processing cost. These studs are typically paired with A194 Grade 8 stainless steel heavy hex nuts for complete material compatibility across the flanged connection.

4. ASTM A193 B16 Stud Bolt Price Chart — Per Piece (INR)

ASTM A193 B16 stud bolts are specified for elevated-temperature service where standard B7 studs may experience creep relaxation. The chromium-molybdenum-vanadium alloy composition provides superior tensile strength retention at temperatures between 450°C and 540°C, making B16 the preferred grade for steam lines, boiler connections, and high-temperature reactor nozzles. The 15–25% price premium over B7 is driven by the costlier alloy rod and additional heat treatment steps required to achieve the B16 mechanical property requirements per ASTM A193.

5. ASTM A320 L7 / A193 B8M (SS316) Stud Bolt Price Chart — Per Piece (INR)

SS316 stud bolts carry the highest per-unit cost among the four grades covered in this guide, reflecting the premium raw material cost driven by nickel (10–12% content) and molybdenum (2–3%) additions. In the Indian market, the designation “L7” is commonly used for SS316 stud bolts, though technically ASTM A320 Grade L7 refers to low-temperature carbon/alloy steel bolting, while ASTM A193 B8M is the correct specification for SS316 austenitic stainless studs. Both are included here as the market treats them interchangeably for procurement purposes. B8M studs are essential for offshore platforms, desalination plants, and chemical process piping where chloride-induced pitting and stress corrosion cracking are primary concerns.

6. Price Per Kg Comparison — All Grades

While per-piece pricing is essential for procurement planning, understanding per-kilogram rates allows engineers to compare stud bolt costs across different sizes and grades on a standardised basis. A critical insight from the data below is that smaller diameters are disproportionately expensive per kilogram because the machining, threading, and handling costs are distributed over a smaller material mass. For budget estimation purposes, the mid-range per-kg rate for each grade provides the most reliable basis for total cost projection across a multi-size bill of materials.

7. Bulk Discount Tiers for Project Orders

Indian fastener suppliers operate on a tiered discount structure that rewards higher order volumes with progressively lower per-unit pricing. For project procurement involving hundreds or thousands of flanged connections, these discounts significantly impact the total fastener budget. The table below outlines typical discount ranges observed across major Indian supplier hubs including Mumbai, Vadodara, Chennai, and Ludhiana. EPC contractors and OEMs with long-term supply agreements may negotiate additional savings beyond the standard tiers shown here, particularly when committing to annual volume contracts with scheduled delivery milestones.

8. Stud Bolt Weight Reference Chart

Accurate weight data is essential for total cost estimation when pricing is negotiated on a per-kilogram basis, and also for logistics planning where shipping costs are weight-sensitive. The weights below are calculated from standard steel density (7,850 kg/m3) using the nominal diameter of each stud bolt size. Actual weights may vary by 2–5% depending on the specific thread profile (UNC, UNF, or metric), thread tolerance class, and chamfer dimensions. For critical weight calculations in offshore or aerospace applications, always verify with the supplier’s certified weight data sheet.

9. How to Calculate Total Stud Bolt Cost for a Project

Estimating the total fastener cost for a piping project requires multiplying the per-piece stud bolt price by the quantity needed per flange connection, then summing across all flange sizes in the bill of materials. The formulas below provide a systematic approach to this calculation, accounting for studs, nuts, and applicable bulk discounts. Remember that nut costs are not included in the per-piece stud bolt prices listed in Sections 2–5 above — you must add 15–25% for matching heavy hex nuts to arrive at the complete bolt-and-nut set cost per connection.

10. Raw Material Cost Drivers in 2026

Understanding the cost structure behind stud bolt pricing helps procurement teams anticipate price movements and time their purchases strategically. The cost of a finished stud bolt breaks down into several components, with raw material being the single largest factor. For B7 alloy steel studs, AISI 4140 round rod accounts for approximately 40–45% of the final price, while thread rolling and machining add another 25–30%. Heat treatment (quench and temper to achieve the required tensile strength of 125 ksi minimum for B7) contributes 10–15%, and testing with mill test certification adds 5–8%.

11. Grade Selection Guide for Flanged Connections

Choosing the right stud bolt grade is not purely a cost decision — it must align with the flange material, operating temperature, pressure class, and corrosion environment specified in the piping design. Using an underspecified grade risks joint failure, while over-specifying in non-critical service wastes procurement budget unnecessarily. The application cards below provide a quick-reference selection matrix based on the most common industrial scenarios encountered in Indian process plants, water treatment facilities, and power generation projects.

Frequently Asked Questions