Related Specifications
Surface Treatments
Certifications
- ISO 9001 - 2015 Certified
- PED 2014/68/EC
- NACE MR0175/ISO 15156-2
- NORSOK M-650
- DFAR
- MERKBLATT AD 2000 W2/W7/W10
Metric hex cap screws manufactured according to ASME B18.2.3.1M fastening specifications.
ASME B18.2.3.1M Hex Cap Screws are widely used in machinery, automotive systems, industrial assemblies, and metric fastening applications. These metric cap screws provide precise threading, dependable fastening performance, and accurate dimensional tolerances for metric industrial systems.

| Nominal Dia.,D,and Thread Pitch | Body Dia., D s | Width Across Flats, S | Width Across Corners, E | Head Height, K | Wrenching Height, K1 1 | Washer Face Thick., C | Washer Face Dia., DW | |||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Max | Min. | Max | Min. | Max | Min. | Max | Min. | Min. | Max | Min. | Min. | |
| ANSI B18.2.3.1M - M5 | 5 | 4.82 | 8 | 7.78 | 9.24 | 8.79 | 3.65 | 3.35 | 2.4 | 0.5 | 0.2 | 7 |
| ANSI B18.2.3.1M - M6 | 6 | 5.82 | 10 | 9.78 | 11.55 | 11.05 | 4.15 | 3.85 | 2.8 | 0.5 | 0.2 | 8.9 |
| ANSI B18.2.3.1M - M8 | 8 | 7.78 | 13 | 12.73 | 15.01 | 14.38 | 5.5 | 5.1 | 3.7 | 0.6 | 0.3 | 11.6 |
| ANSI B18.2.3.1M - aM10 | 10 | 9.78 | 15 | 14.73 | 17.32 | 16.64 | 6.63 | 6.17 | 4.5 | 0.6 | 0.3 | 13.6 |
| ANSI B18.2.3.1M - M10 | 10 | 9.78 | 16 | 15.73 | 18.48 | 17.77 | 6.63 | 6.17 | 4.5 | 0.6 | 0.3 | 14.6 |
| ANSI B18.2.3.1M - M12 | 12 | 11.73 | 18 | 17.73 | 20.78 | 20.03 | 7.76 | 7.24 | 5.2 | 0.6 | 0.3 | 16.6 |
| ANSI B18.2.3.1M - M14 | 14 | 13.73 | 21 | 20.67 | 24.25 | 23.35 | 9.09 | 8.51 | 6.2 | 0.6 | 0.3 | 19.6 |
| ANSI B18.2.3.1M - M16 | 16 | 15.73 | 24 | 23.67 | 27.71 | 26.75 | 10.32 | 9.68 | 7 | 0.8 | 0.4 | 22.5 |
| ANSI B18.2.3.1M - M20 | 20 | 19.67 | 30 | 29.16 | 34.64 | 32.95 | 12.88 | 12.12 | 8.8 | 0.8 | 0.4 | 27.7 |
| ANSI B18.2.3.1M - M24 | 24 | 23.67 | 36 | 35 | 41.57 | 39.55 | 15.44 | 14.56 | 10.5 | 0.8 | 0.4 | 33.2 |
| ANSI B18.2.3.1M - M30 | 30 | 29.67 | 46 | 45 | 53.12 | 50.85 | 19.48 | 17.92 | 13.1 | 0.8 | 0.4 | 42.7 |
| ANSI B18.2.3.1M - M36 | 36 | 35.61 | 55 | 53.8 | 63.51 | 60.79 | 23.38 | 21.62 | 15.8 | 0.8 | 0.4 | 51.1 |
| ANSI B18.2.3.1M - M42 | 42 | 41.38 | 65 | 62.9 | 75.06 | 71.71 | 26.97 | 25.03 | 18.2 | 1 | 0.5 | 59.8 |
| ANSI B18.2.3.1M - M48 | 48 | 47.38 | 75 | 72.6 | 86.6 | 82.76 | 31.07 | 28.93 | 21 | 1 | 0.5 | 69 |
| ANSI B18.2.3.1M - M56 | 56 | 55.26 | 85 | 82.2 | 98.15 | 93.71 | 36.2 | 33.8 | 24.5 | 1 | 0.5 | 78.1 |
| ANSI B18.2.3.1M - M64 | 64 | 63.26 | 95 | 91.8 | 109.7 | 104.65 | 41.32 | 38.68 | 28 | 1 | 0.5 | 87.2 |
| ANSI B18.2.3.1M - M72 | 72 | 71.26 | 105 | 101.4 | 121.24 | 115.6 | 46.45 | 43.55 | 31.5 | 1.2 | 0.6 | 96.3 |
| ANSI B18.2.3.1M - M80 | 80 | 79.26 | 115 | 111 | 132.72 | 126.54 | 51.58 | 48.42 | 35 | 1.2 | 0.6 | 105.4 |
| ANSI B18.2.3.1M - M90 | 90 | 89.13 | 130 | 125.5 | 150.11 | 143.07 | 57.74 | 54.26 | 39.2 | 1.2 | 0.6 | 119.2 |
| ANSI B18.2.3.1M - M100 | 100 | 99.13 | 145 | 140 | 167.43 | 159.6 | 63.9 | 60.1 | 43.4 | 1.2 | 0.6 | 133 |
|
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| Nominal Screw Diameter and Thread Pitch |
Fillet Transition Diameter, Da |
Fillet Length, Lf | Fillet Radius for Short and Long Screws, R, Min. |
Body Diameter for Short Screws, Dsi, Min. |
||
|---|---|---|---|---|---|---|
| For Short Screws, Min. |
For Short and Long Screws, Max. |
For Long Screws, Max. |
For Short Screws, Max. |
|||
| M5 | 5.1 | 5.7 | 1.2 | 0.7 | 0.2 | 4.36 |
| M6 | 6.2 | 6.8 | 1.4 | 0.9 | 0.25 | 5.21 |
| M8 | 8.3 | 9.2 | 2.0 | 1.1 | 0.4 | 7.04 |
| M10 | 10.2 | 11.2 | 2.0 | 1.2 | 0.4 | 8.86 |
| M12 | 12.2 | 13.7 | 3.0 | 1.3 | 0.6 | 10.68 |
| M14 | 14.1 | 15.7 | 3.0 | 1.4 | 0.6 | 12.50 |
| M16 | 16.5 | 17.7 | 3.0 | 1.6 | 0.6 | 14.50 |
| M20 | 20.7 | 22.4 | 4.0 | 2.1 | 0.8 | 18.16 |
| M24 | 24.5 | 26.4 | 4.0 | 2.3 | 0.8 | 21.80 |
| M30 | 30.8 | 33.4 | 6.0 | 3.0 | 1.0 | 27.46 |
| M36 | 36.6 | 39.4 | 6.0 | 3.1 | 1.0 | 33.12 |
| M42 | . . . | 45.6 | 8.0 | 3.4 | 1.2 | 38.78 |
| M48 | . . . | 52.6 | 10.0 | 4.0 | 1.6 | 44.43 |
| M56 | . . . | 63.0 | 12.0 | 4.8 | 2.0 | 52.09 |
| M64 | . . . | 71.0 | 13.0 | 5.0 | 2.0 | 59.74 |
| M72 | . . . | 79.0 | 13.0 | 5.0 | 2.0 | 67.74 |
| M80 | . . . | 87.0 | 13.0 | 5.0 | 2.0 | 75.74 |
| M90 | . . . | 97.0 | 13.0 | 5.0 | 2.5 | 85.74 |
| M100 | . . . | 107.0 | 13.0 | 5.5 | 2.5 | 95.72 |
| Nominal Screw Diameter and Thread Pitch | Thread Length, B, Ref | Transition Thread Length, X, Ref | Screws Threaded Full Length | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Screw Lengths, L ≤ 125 | Screw Lengths, L > 125 & ≤ 200 | Screw Lengths, L > 200 | Screw Lengths, L, Under | Unthreaded Length Under Head, A, Max. [Note (1)] | Screw Lengths, L | Unthreaded Length Under Head, A, Max. |
|||
| At Least | Under | ||||||||
| M5 | 16 | 22 | 35 | 4.0 | 10 | 1.2 | 10 | 25 | 2.4 |
| M6 | 18 | 24 | 37 | 5.0 | 12 | 1.5 | 12 | 30 | 3.0 |
| M8 | 22 | 28 | 41 | 6.25 | 16 | 1.9 | 16 | 40 | 4.0 |
| M10 | 26 | 32 | 45 | 7.5 | 20 | 2.2 | 20 | 45 | 4.5 |
| M12 | 30 | 36 | 49 | 8.75 | 24 | 2.6 | 24 | 50 | 5.3 |
| M14 | 34 | 40 | 53 | 10.0 | 28 | 3.0 | 28 | 60 | 6.0 |
| M16 | 38 | 44 | 57 | 10.0 | 32 | 3.0 | 32 | 65 | 6.0 |
| M20 | 46 | 52 | 65 | 12.5 | 40 | 3.8 | 40 | 80 | 7.5 |
| M24 | 54 | 60 | 73 | 15.0 | ... | ... | ... | 90 | 9.0 |
| M30 | 66 | 72 | 85 | 17.5 | ... | ... | ... | 110 | 10.5 |
| M36 | ... | 84 | 97 | 20.0 | ... | ... | ... | 140 | 12.0 |
| M42 | ... | 96 | 109 | 22.5 | ... | ... | ... | 160 | 13.5 |
| M48 | ... | 108 | 121 | 25.0 | ... | ... | ... | 180 | 15.0 |
| M56 | ... | ... | 137 | 27.5 | ... | ... | ... | 220 | 16.5 |
| M64 | ... | ... | 153 | 30.0 | ... | ... | ... | 260 | 18.0 |
| M72 | ... | ... | 169 | 30.0 | ... | ... | ... | 280 | 18.0 |
| M80 | ... | ... | 185 | 30.0 | ... | ... | ... | 300 | 18.0 |
| M90 | ... | ... | 205 | 30.0 | ... | ... | ... | 340 | 18.0 |
| M100 | ... | ... | 225 | 30.0 | ... | ... | ... | 360 | 18.0 |
| Nominal Length | Nominal Screw Diameter | ||||||||
|---|---|---|---|---|---|---|---|---|---|
| Over | Thru | M5 | M6 | M8 | M10 | M12 | M14 | M16-M24 | >M24 |
| 6 | 10 | ±0.29 | ±0.29 | ±0.29 | ±0.29 | ... | ... | ... | ... |
| 10 | 18 | ±0.35 | ±0.35 | ±0.35 | ±0.35 | ±0.35 | ±0.35 | ±0.35 | ... |
| 18 | 30 | ±0.42 | ±0.42 | ±0.42 | ±0.42 | ±0.42 | ±0.42 | ±0.42 | ±1.05 |
| 30 | 50 | ±0.50 | ±0.50 | ±0.50 | ±0.50 | ±0.50 | ±0.50 | ±0.50 | ±1.25 |
| 50 | 60 | ±1.50 | ±0.60 | ±0.60 | ±0.60 | ±0.60 | ±0.60 | ±0.60 | ±1.50 |
| 60 | 80 | ±1.50 | ±1.50 | ±0.60 | ±0.60 | ±0.60 | ±0.60 | ±0.60 | ±1.50 |
| 80 | 100 | ±1.75 | ±1.75 | ±1.75 | ±0.70 | ±0.70 | ±0.70 | ±0.70 | ±1.75 |
| 100 | 120 | ±1.75 | ±1.75 | ±1.75 | ±1.75 | ±0.70 | ±0.70 | ±0.70 | ±1.75 |
| 120 | 140 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±0.80 | ±0.80 | ±2.00 |
| 140 | 150 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±0.80 | ±2.00 |
| 150 | 180 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 | ±2.00 |
| 180 | 250 | ±2.30 | ±2.30 | ±2.30 | ±2.30 | ±2.30 | ±2.30 | ±2.30 | ±2.30 |
| 250 | 315 | ±2.60 | ±2.60 | ±2.60 | ±2.60 | ±2.60 | ±2.60 | ±2.60 | ±2.60 |
| 315 | 400 | ±2.85 | ±2.85 | ±2.85 | ±2.85 | ±2.85 | ±2.85 | ±2.85 | ±2.85 |
| 400 | 500 | ±3.15 | ±3.15 | ±3.15 | ±3.15 | ±3.15 | ±3.15 | ±3.15 | ±3.15 |
ASTM F468 covers copper (C11000), brass (C26000, C27000, C46200, C46400), bronze (C51000 phosphor, C61300/C61400/C63000 aluminum, C64200, C65100/C65500/C66100 silicon, C67500 manganese), cupro-nickel (C71000, C71500), nickel-base alloys (N04400 Monel 400, N04405, N05500 Monel K-500, N06059 Alloy 59, N06625 Inconel 625, N06686, N10001 Hastelloy B-2, N10276 Hastelloy C-276), aluminum (A92024, A96061, A97075), and titanium (R50250 Gr 1, R50400 Gr 2, R50700 Gr 4, R56400 Gr 5, R56401 Gr 23 ELI, R52400 Gr 7, R58640 Gr 19, R55111 Gr 32) - all available for this product family at TorqBolt.
This product follows ASME B18.2 3 1M, the dimensional standard for din 933. Material chemistry, mechanical properties, and acceptance criteria follow ASTM F468 / F468M for nonferrous bolting. TorqBolt supplies both inch-series and metric sizes per the applicable ASME or ISO drawing.
For seawater bolting per F468: Monel 400 (N04400) and Monel K-500 (N05500) resist chloride stress-corrosion cracking and HF acid; nickel-aluminum bronze C63000 is the standard high-strength marine fastener; cupro-nickel C71500 is preferred for condenser tube-sheet bolting; naval brass C46400 is the lower-cost option for routine marine hardware; titanium Grade 2 (R50400) is the premium choice for severe chloride + chemical service.
Most F468 nickel and titanium grades are NACE MR0175 / ISO 15156-listed: Monel 400 (N04400), Monel K-500 (N05500) conditional, Inconel 625 (N06625), Hastelloy B-2 (N10001), Hastelloy C-276 (N10276), Alloy 59 (N06059), Alloy 686 (N06686), and all titanium grades (R50400, R52400, R56400, R56401). Aluminum bronzes are generally not preferred for sour service. TorqBolt provides NACE-compliant heat-treat and hardness reports on request.