High Tensile Fasteners
Alloy & Boron Steel Grade 8.8 / 10.9 / 12.9 Fasteners
High Torque, Extreme Stress & Vibration Resistant Solutions
Product Overview
Kuldevi Forge & Fittings is a leading manufacturer and supplier of high-performance High Tensile Fasteners in India. These fasteners are specially engineered in carbon steel and boron steel alloy grades to withstand high torque loads, extreme mechanical stress, and high-vibration conditions.
Our high tensile bolts and nuts are manufactured in accordance with major standards (IS, DIN, ISO, BS, ASME, ASTM, JIS, EN, AS) and are predominantly supplied in Grade 8.8, 10.9, and 12.9. These grades represent varying tensile strengths, with Grade 12.9 being the premium choice for heavy forged components and automotive engines demanding maximum safety preloads.
Our production capabilities cover a wide variety of designs, including Hex Bolts, Stud Bolts, High Strength Structural Bolts, Eye Bolts, U-Bolts, Flange Bolts, Allen Bolts, and Track Shoe Bolts. Sizes range from thread diameters M2 to M100 and lengths from 6mm to 500mm, coated with anti-rust treatments like Hot-Dip Galvanizing, Zinc Plating, or specialized Teflon/Xylan coatings.
Technical Specifications
| Product Category | High Tensile (HT) Bolts, Nuts, Studs, and Washers |
|---|---|
| Material Grades | Grade 8.8, Grade 10.9, Grade 12.9 (Alloy Steel, Boron Steel, Carbon Steel) |
| Thread Size Range | M2 to M100 (Metric) & 1/4" to 4" (Inch size) |
| Bolts Diameter | M3 to M60 |
| Available Lengths | 6mm to 500mm (Fully threaded up to 6" for ASME B18.6.3 standard) |
| Standard Compliance | IS, BS, BSW, DIN, ASME, ASTM, ISO, JIS, EN, AS, GB (e.g. ISO 4017, DIN 931/933, DIN 912, DIN 603, DIN 6923) |
| Thread Requirements | ASME B1.1, UNC & UNF, Class 2A / 2B |
| Finish & Coatings | Zinc Plated (Yellow, White, Blue, Black), Passivated, Hot-Dip Galvanized (HDG), Black Oxide, Geomet, Dacromet, Sandblast, Anodized, Chrome/Nickel plated, Teflon, Xylan, Zinc-Nickel, Rust Preventive Oil |
| Head & Drive Styles | Hex, Hex Flange, Socket Cap (Allen), CSK, Button Head, grub/Set Screws, T-Head, Triangular Head, Square, Round |
| Production Technology | Cold Forged / Cold Headed, Hot Forged, Insert Tapping, Heat Treatment |
| Testing & Inspection | Chemical Analysis, Tensile Strength Testing, Hardness Testing (HRC37-44 for 12.9 Grade), Dimensional Inspection, Salt Fog Test, Thread Gauge Verification |
| Applications | Wind towers, Nuclear power stations, Railways, Automotive, heavy construction, electronic industrial systems |
Material Composition Capabilities
| Material Category | Applicable Steel Grades & Standards |
|---|---|
| Stainless Steel | SS201, SS303, SS304, SS316, SS410, SS420 (High Tensile Corrosion Resistant) |
| Structural Alloy Steel | SCM435, C10B21, C10B33, C45(K1045), C46(K1046) |
| Carbon Steel | C1006, C1010, C1018, C1022, C1035K, C1045, C20 |
| Non-Ferrous Alloys | Bronze (C51000, C52100, C54400), Brass (C36000, C26800, C37700, C38500), Aluminum (Al6061, Al6063) |
| Free Cutting Steel | Iron 1213, 12L14, 1215 |
Metric Threads Hex Bolts Dimensions (IS 1364 / ISO 4014)
All dimensions in millimeters (mm)
| Dia | Pitch (mm) | Across Flats (S, Max) | Across Corners (e, Min) | Head Height (K, Nom) | Thread Length (b, L <= 125) | Thread Length (b, 125 < L <= 200) | Thread Length (b, L > 200) |
|---|---|---|---|---|---|---|---|
| M4 | 0.7 | 7.0 | 7.66 | 2.8 | 14 | 20 | 33 |
| M5 | 0.8 | 8.0 | 8.79 | 3.5 | 16 | 22 | 35 |
| M6 | 1.0 | 10.0 | 11.05 | 4.0 | 18 | 24 | 37 |
| M8 | 1.25 | 13.0 | 14.38 | 5.3 | 22 | 28 | 41 |
| M10 | 1.5 | 16.0 | 17.77 | 6.4 | 26 | 32 | 45 |
| M12 | 1.75 | 18.0 | 20.03 | 7.5 | 30 | 36 | 49 |
| M14 | 2.0 | 21.0 | 23.36 | 8.8 | 34 | 40 | 53 |
| M16 | 2.0 | 24.0 | 26.75 | 10.0 | 38 | 44 | 57 |
| M18 | 2.5 | 27.0 | 30.14 | 11.5 | 42 | 48 | 61 |
| M20 | 2.5 | 30.0 | 33.53 | 12.5 | 46 | 52 | 65 |
| M22 | 2.5 | 34.0 | 37.72 | 14.0 | 50 | 56 | 69 |
| M24 | 3.0 | 36.0 | 39.98 | 15.0 | 54 | 60 | 73 |
| M27 | 3.0 | 41.0 | 45.2 | 17.0 | 60 | 66 | 79 |
| M30 | 3.5 | 46.0 | 50.85 | 18.7 | 66 | 72 | 85 |
| M33 | 3.5 | 50.0 | 55.37 | 21.0 | - | 78 | 91 |
| M36 | 4.0 | 55.0 | 60.79 | 22.5 | - | 84 | 97 |
| M42 | 4.5 | 65.0 | 71.3 | 26.0 | - | 96 | 109 |
| M48 | 5.0 | 75.0 | 82.6 | 30.0 | - | 108 | 121 |
| M52 | 5.0 | 80.0 | 88.25 | 33.0 | - | 116 | 129 |
BSW / BSF Threads Hex Bolts Dimensions (BS 1083)
All dimensions in inches (in)
| Dia | BSW Pitch (TPI) | BSF Pitch (TPI) | Across Flats (S, Max) | Across Corners (e, Max) | Head Height (K, Max) | Thread Length (b, Min) |
|---|---|---|---|---|---|---|
| 1/4" | 20 | 26 | 0.445 | 0.51 | 0.176 | 2D |
| 5/16" | 18 | 22 | 0.525 | 0.61 | 0.218 | 2D |
| 3/8" | 16 | 20 | 0.600 | 0.69 | 0.260 | 2D |
| 7/16" | 14 | 18 | 0.710 | 0.82 | 0.302 | 2D |
| 1/2" | 12 | 16 | 0.820 | 0.95 | 0.343 | 2D |
| 9/16" | 12 | 16 | 0.920 | 1.06 | 0.375 | 2D |
| 5/8" | 11 | 14 | 1.010 | 1.17 | 0.417 | 2D |
| 3/4" | 10 | 12 | 1.200 | 1.39 | 0.500 | 2D |
| 7/8" | 9 | 11 | 1.300 | 1.50 | 0.583 | 2D |
| 1" | 8 | 10 | 1.480 | 1.71 | 0.666 | 2D |
| 1 1/8" | 7 | 9 | 1.670 | 1.93 | 0.750 | 2D |
| 1 1/4" | 7 | 9 | 1.860 | 2.15 | 0.830 | 2D |
| 1 1/2" | 6 | 8 | 2.220 | 2.56 | 1.000 | 2D |
| 1 3/4" | 5 | 7 | 2.580 | 2.98 | 1.170 | 2D |
| 2" | 4.5 | 7 | 2.760 | 3.19 | 1.330 | 2D |
Unified UNC / UNF Threads Hex Bolts Dimensions (BS 1768)
All dimensions in inches (in)
| Dia | UNC Pitch (TPI) | UNF Pitch (TPI) | Across Flats (S, Max) | Across Corners (e, Max) | Head Height (K, Max) | Thread Length (b, Min) |
|---|---|---|---|---|---|---|
| 1/4" | 20 | 28 | 0.437 | 0.505 | 0.163 | 2D + 1/4” (<=6” length) |
| 5/16" | 18 | 24 | 0.500 | 0.577 | 0.211 | 2D + 1/4” (<=6” length) |
| 3/8" | 16 | 24 | 0.562 | 0.650 | 0.243 | 2D + 1/4” (<=6” length) |
| 7/16" | 14 | 24 | 0.625 | 0.722 | 0.291 | 2D + 1/4” (<=6” length) |
| 1/2" | 13 | 20 | 0.750 | 0.866 | 0.323 | 2D + 1/4” (<=6” length) |
| 9/16" | 12 | 20 | 0.812 | 0.938 | 0.371 | 2D + 1/4” (<=6” length) |
| 5/8" | 11 | 18 | 0.937 | 1.083 | 0.403 | 2D + 1/4” (<=6” length) |
| 3/4" | 10 | 16 | 1.125 | 1.300 | 0.483 | 2D + 1/4” (<=6” length) |
| 7/8" | 9 | 14 | 1.312 | 1.515 | 0.563 | 2D + 1/4” (<=6” length) |
| 1" | 8 | 12 | 1.500 | 1.732 | 0.627 | 2D + 1/4” (<=6” length) |
| 1 1/8" | 7 | - | 1.687 | 1.948 | 0.718 | 2D + 1/2” (>6” length) |
| 1 1/4" | 7 | - | 1.875 | 2.165 | 0.813 | 2D + 1/2” (>6” length) |
| 1 3/8" | 6 | - | 2.062 | 2.382 | 0.878 | 2D + 1/2” (>6” length) |
| 1 1/2" | 6 | - | 2.250 | 2.598 | 0.974 | 2D + 1/2” (>6” length) |
| 1 3/4" | 5 | - | 2.625 | 3.031 | 1.134 | 2D + 1/2” (>6” length) |
| 2" | 4.5 | - | 3.000 | 3.464 | 1.263 | 2D + 1/2” (>6” length) |
Specialized High Tensile Fasteners Info
Structural Fasteners (Friction Grip)
We supply High Tensile Friction Grip (HTFG) structural bolts conforming to IS 3757-1985 for high-stress steel connection frameworks, coupled with matching nuts conforming to IS 6623-2004.
- Standard Sizes: M16 x 40 to M30 x 200
- Grade options: 8.8S and 10.9S
Track Shoe Fasteners
Engineered specifically for heavy earthmovers and military crawler tracks. Manufactured in Grade 12.9 to avoid thread shear under sudden impact.
- 5/8” UNF x 2 1/4” with Square Nuts
- 3/4” UNF x 2 3/8” with Square Nuts
- 7/8” UNF x 2 5/8” with Square Nuts