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Socket head cap screws, inch #0 to 1-1/2 (ASME B18.3): head, hex socket, key engagement — full size table + models #0 to 1
What are the head diameter, head height and hex key size of a #4-40, #8-32, 1/4-20, 5/8-11 or 1 in socket head cap screw? · Standard part · basis: A maker sheet carrying the ASME B18.3-1998 SHCS table (checked against AFT Fasteners' ASME B18.3-2003 table for #10, 1/4, 1/2 and 1), thread series from ASME B1.1 (Engineering ToolBox); 18 envelope models as files
Also called: socket head cap screw dimensions chart, 4-40 socket head cap screw head diameter, 1/4-20 shcs head diameter, 8-32 socket head cap screw hex key, socket head cap screw size chart inch, shcs counterbore, 5/8-11 socket head cap screw head height, 3/4-10 socket head cap screw hex size, #0-80 socket head cap screw, asme b18.3 socket head cap screw, shcs head dia and height table, socket cap screw key e
Exact dimensions. Every file is drawn at true size with no tolerance added. The holes and pins that meet another part are listed below under Mating features, with the fit each joint needs; open those by your process's clearance before making the part. Mating features
- length
- 50.8 mm
- width
- 38.1 mm
- height
- 76.2 mm
Notes
- Inch dimensions per ASME B18.3 as printed on the sheet: body diameter D max / min, head diameter A max / min, head height H max / min, hex socket size (nominal), key engagement T min, wall thickness min, fillet transition diameter max / min, top and bottom chamfer or radius max, basic thread length LT (1/4 to 1 in). Sizes #0 to 1-1/2 are tabulated; head height equals the nominal diameter on every size. The sheet's column letters for the last columns are not decoded in the text read, so those columns are named by their printed words. AFT's ASME B18.3-2003 table prints the same D, A, H and key engagement values for #10, 1/4, 1/2 and 1 (its 'J' column holds the fillet transition diameter, which equals the sheet's value), so the two editions agree on these.
- Overlap: the pages socket-head-cap-screws-inch (#10-24, #10-32, 5/16-18, 3/8-16, 1/2-13, existing) and imperial-machine-screws (#4 to 1/4-20) already hold a few of these sizes with their own files. This page is the complete table; its files use the dimensions on this page (head and height maxima, hex across flats, key engagement) and a different example length rule, so they are not identical to the older files.
- Files are Xem-drawn envelopes at true nominal size: head cylinder A max x H max, hex socket at the nominal across-flats size and the minimum key-engagement depth, plain shank at D max (the real thread is smaller at the root). No top chamfer, no under-head fillet, no socket cone (those are published as limits or not as numbers). Example lengths (0.25 in for #0 to #3, 0.5 in for #4 to #10, 1 in for 1/4 to 3/8, 1.5 in for 7/16 to 5/8, 2 in for 3/4 to 1) are Xem's choice. Sizes 1-1/4 and 1-1/2 are in the table only.
- The sheet gives the length tolerance, thread lengths and mechanical properties for stainless steel; strength values are not repeated here. Metric: socket-head-cap-screws-metric. Button head, flat head and low head inch socket screws are separate pages.
Socket head cap screws, inch #0 to 1-1/2 (ASME B18.3): head, hex… size chart
| size | TPI UNC / UNF | body D max / min (in) | head A max / min (in) | head height H max / min (in) | hex socket nominal | key engagement T min (in) | wall min (in) | fillet transition dia max / min (in) | top chamfer max (in) | bottom chamfer max (in) | basic thread length LT (in) | D max (mm, computed) | head dia x height max (mm, computed) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| #0 | — / 80 | 0.0600 / 0.0568 | 0.096 / 0.091 | 0.060 / 0.057 | .050 in | 0.025 | 0.020 | 0.074 / 0.063 | 0.004 | 0.007 | — | 1.524 | 2.44 x 1.52 |
| #1 | 64 / 72 | 0.0730 / 0.0695 | 0.118 / 0.112 | 0.073 / 0.070 | 1/16 in | 0.031 | 0.025 | 0.087 / 0.076 | 0.005 | 0.007 | — | 1.854 | 3.00 x 1.85 |
| #2 | 56 / 64 | 0.0860 / 0.0822 | 0.140 / 0.134 | 0.086 / 0.083 | 5/64 in | 0.038 | 0.029 | 0.102 / 0.090 | 0.008 | 0.007 | — | 2.184 | 3.56 x 2.18 |
| #3 | 48 / 56 | 0.0990 / 0.0949 | 0.161 / 0.154 | 0.099 / 0.095 | 5/64 in | 0.044 | 0.034 | 0.115 / 0.103 | 0.008 | 0.007 | — | 2.515 | 4.09 x 2.51 |
| #4 | 40 / 48 | 0.1120 / 0.1075 | 0.183 / 0.176 | 0.112 / 0.108 | 3/32 in | 0.051 | 0.038 | 0.130 / 0.118 | 0.009 | 0.008 | — | 2.845 | 4.65 x 2.84 |
| #5 | 40 / 44 | 0.1250 / 0.1202 | 0.205 / 0.198 | 0.125 / 0.121 | 3/32 in | 0.057 | 0.043 | 0.145 / 0.132 | 0.012 | 0.008 | — | 3.175 | 5.21 x 3.17 |
| #6 | 32 / 40 | 0.1380 / 0.1329 | 0.226 / 0.218 | 0.138 / 0.134 | 7/64 in | 0.064 | 0.047 | 0.158 / 0.145 | 0.013 | 0.008 | — | 3.505 | 5.74 x 3.51 |
| #8 | 32 / 36 | 0.1640 / 0.1585 | 0.270 / 0.262 | 0.164 / 0.159 | 9/64 in | 0.077 | 0.056 | 0.188 / 0.173 | 0.014 | 0.008 | — | 4.166 | 6.86 x 4.17 |
| #10 | 24 / 32 | 0.1900 / 0.1840 | 0.312 / 0.303 | 0.190 / 0.185 | 5/32 in | 0.090 | 0.065 | 0.218 / 0.202 | 0.018 | 0.008 | — | 4.826 | 7.92 x 4.83 |
| 1/4 | 20 / 28 | 0.2500 / 0.2435 | 0.375 / 0.365 | 0.250 / 0.244 | 3/16 in | 0.120 | 0.095 | 0.278 / 0.262 | 0.025 | 0.010 | 1.000 | 6.350 | 9.52 x 6.35 |
| 5/16 | 18 / 24 | 0.3125 / 0.3053 | 0.469 / 0.457 | 0.312 / 0.306 | 1/4 in | 0.151 | 0.119 | 0.347 / 0.329 | 0.033 | 0.010 | 1.125 | 7.938 | 11.91 x 7.92 |
| 3/8 | 16 / 24 | 0.3750 / 0.3678 | 0.562 / 0.550 | 0.375 / 0.368 | 5/16 in | 0.182 | 0.143 | 0.415 / 0.398 | 0.040 | 0.010 | 1.250 | 9.525 | 14.27 x 9.52 |
| 7/16 | 14 / 20 | 0.4375 / 0.4294 | 0.656 / 0.642 | 0.438 / 0.430 | 3/8 in | 0.213 | 0.166 | 0.484 / 0.465 | 0.047 | 0.015 | 1.375 | 11.112 | 16.66 x 11.13 |
| 1/2 | 13 / 20 | 0.5000 / 0.4919 | 0.750 / 0.735 | 0.500 / 0.492 | 3/8 in | 0.245 | 0.190 | 0.552 / 0.532 | 0.055 | 0.015 | 1.500 | 12.700 | 19.05 x 12.70 |
| 5/8 | 11 / 18 | 0.6250 / 0.6163 | 0.938 / 0.921 | 0.625 / 0.616 | 1/2 in | 0.307 | 0.238 | 0.689 / 0.664 | 0.070 | 0.015 | 1.750 | 15.875 | 23.83 x 15.88 |
| 3/4 | 10 / 16 | 0.7500 / 0.7406 | 1.125 / 1.107 | 0.750 / 0.740 | 5/8 in | 0.370 | 0.285 | 0.828 / 0.801 | 0.085 | 0.015 | 2.000 | 19.050 | 28.57 x 19.05 |
| 7/8 | 9 / 14 | 0.8750 / 0.8647 | 1.312 / 1.293 | 0.875 / 0.864 | 3/4 in | 0.432 | 0.333 | 0.963 / 0.933 | 0.100 | 0.020 | 2.250 | 22.225 | 33.32 x 22.22 |
| 1 | 8 / 12 | 1.0000 / 0.9886 | 1.500 / 1.479 | 1.000 / 0.988 | 3/4 in | 0.495 | 0.380 | 1.100 / 1.069 | 0.114 | 0.020 | 2.500 | 25.400 | 38.10 x 25.40 |
| 1-1/4 | 7 / 12 | 1.2500 / 1.2336 | 1.875 / 1.852 | 1.250 / 1.236 | 7/8 in | 0.620 | 0.475 | 1.370 / 1.334 | 0.144 | 0.020 | — | 31.750 | 47.62 x 31.75 |
| 1-1/2 | 6 / 12 | 1.5000 / 1.4818 | 2.250 / 2.224 | 1.500 / 1.485 | 1 in | 0.745 | 0.570 | 1.640 / 1.602 | 0.176 | 0.020 | — | 38.100 | 57.15 x 38.10 |
Mating features
Drawn at the exact size. Open press, slide, run and socket features by your process's clearance (tolerances by process); leave designed gaps and clamp fits as drawn.
| feature | exact | mates with | fit | files |
|---|---|---|---|---|
| shank (thread as plain cylinder) | D max per size: #4 Ø2.845, #10 Ø4.826, 1/4 Ø6.350, 3/8 Ø9.525, 1/2 Ø12.700, 1 Ø25.400 mm | tapped hole at the tap drill, or clearance hole (close / normal / loose), see thread-reference-tap-drills-clearance | designed | all |
| head | A max × H max per size: #8 0.270 × 0.164 in, 1/4 0.375 × 0.250 in (9.53 × 6.35 mm), 3/8 0.562 × 0.375 in, 1/2 0.750 × 0.500 in | round counterbore: Ø = A max + your process clearance, depth = H max | slide | shcs-* |
| hex socket | nominal across flats: #8 9/64, 1/4 3/16, 5/16 1/4, 3/8 5/16, 1/2 3/8, 5/8 1/2 in; key engagement 0.120 in min for 1/4 | hex key of the same size (inch series) | slide | shcs-* |
Where the files are
Other publishers' files are linked, not hosted. "verify" = check the license at the link before commercial use.
| Stainless-steel fastener maker sheet (hosted on a Shopify CDN, ASME B18.3-1998 table) | Socket head cap screw dimensions #0 to 1-1/2: body D, head A, head height H, hex socket, key engagement, wall, chamfers, thread length LT | web | Publisher's page; dimensions are facts |
| AFT Fasteners | Standard socket head cap screw dimensions, ASME B18.3-2003 (cross-check of D, A, H, key engagement for #10, 1/4, 1/2, 1) | web | Publisher's page; dimensions are facts |
| Engineering ToolBox | ANSI/ASME B1.1 Unified National threads, UNC and UNF: TPI, major diameter in / mm, tap drill mm, pitch mm, #0 to 4 in | web | Publisher's page; dimensions are facts |
| McMaster-Carr | Socket head screws (cap, flat, set) (free STEP/IGES per part, for your own design use; no redistribution) | STEP, IGES, PDF | McMaster-Carr site terms: personal design use, no redistribution verify |
Free files
★ Free files 18 parts. Generated by Xem Studio from the standard; threads are plain cylinders at major diameter. CC BY 4.0. index.json
| shcs-no0-80x6.35mm | #0 socket head cap screw envelope: head Ø2.44 mm (A max 0.096 in) x 1.52 mm (H max 0.060 in), hex socket .050 in across flats x 0.025 in deep (key engagement min), plain Ø1.524 mm shank (D max), example length under the head 0.25 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no1-64x6.35mm | #1 socket head cap screw envelope: head Ø3.00 mm (A max 0.118 in) x 1.85 mm (H max 0.073 in), hex socket 1/16 in across flats x 0.031 in deep (key engagement min), plain Ø1.854 mm shank (D max), example length under the head 0.25 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no2-56x6.35mm | #2 socket head cap screw envelope: head Ø3.56 mm (A max 0.140 in) x 2.18 mm (H max 0.086 in), hex socket 5/64 in across flats x 0.038 in deep (key engagement min), plain Ø2.184 mm shank (D max), example length under the head 0.25 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no3-48x6.35mm | #3 socket head cap screw envelope: head Ø4.09 mm (A max 0.161 in) x 2.51 mm (H max 0.099 in), hex socket 5/64 in across flats x 0.044 in deep (key engagement min), plain Ø2.515 mm shank (D max), example length under the head 0.25 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no4-40x12.7mm | #4 socket head cap screw envelope: head Ø4.65 mm (A max 0.183 in) x 2.84 mm (H max 0.112 in), hex socket 3/32 in across flats x 0.051 in deep (key engagement min), plain Ø2.845 mm shank (D max), example length under the head 0.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no5-40x12.7mm | #5 socket head cap screw envelope: head Ø5.21 mm (A max 0.205 in) x 3.17 mm (H max 0.125 in), hex socket 3/32 in across flats x 0.057 in deep (key engagement min), plain Ø3.175 mm shank (D max), example length under the head 0.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no6-32x12.7mm | #6 socket head cap screw envelope: head Ø5.74 mm (A max 0.226 in) x 3.51 mm (H max 0.138 in), hex socket 7/64 in across flats x 0.064 in deep (key engagement min), plain Ø3.505 mm shank (D max), example length under the head 0.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no8-32x12.7mm | #8 socket head cap screw envelope: head Ø6.86 mm (A max 0.270 in) x 4.17 mm (H max 0.164 in), hex socket 9/64 in across flats x 0.077 in deep (key engagement min), plain Ø4.166 mm shank (D max), example length under the head 0.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-no10-24x12.7mm | #10 socket head cap screw envelope: head Ø7.92 mm (A max 0.312 in) x 4.83 mm (H max 0.190 in), hex socket 5/32 in across flats x 0.090 in deep (key engagement min), plain Ø4.826 mm shank (D max), example length under the head 0.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-1-4-20x25.4mm | 1/4 socket head cap screw envelope: head Ø9.52 mm (A max 0.375 in) x 6.35 mm (H max 0.250 in), hex socket 3/16 in across flats x 0.120 in deep (key engagement min), plain Ø6.350 mm shank (D max), example length under the head 1.0 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-5-16-18x25.4mm | 5/16 socket head cap screw envelope: head Ø11.91 mm (A max 0.469 in) x 7.92 mm (H max 0.312 in), hex socket 1/4 in across flats x 0.151 in deep (key engagement min), plain Ø7.938 mm shank (D max), example length under the head 1.0 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-3-8-16x25.4mm | 3/8 socket head cap screw envelope: head Ø14.27 mm (A max 0.562 in) x 9.52 mm (H max 0.375 in), hex socket 5/16 in across flats x 0.182 in deep (key engagement min), plain Ø9.525 mm shank (D max), example length under the head 1.0 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-7-16-14x38.1mm | 7/16 socket head cap screw envelope: head Ø16.66 mm (A max 0.656 in) x 11.13 mm (H max 0.438 in), hex socket 3/8 in across flats x 0.213 in deep (key engagement min), plain Ø11.112 mm shank (D max), example length under the head 1.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-1-2-13x38.1mm | 1/2 socket head cap screw envelope: head Ø19.05 mm (A max 0.750 in) x 12.70 mm (H max 0.500 in), hex socket 3/8 in across flats x 0.245 in deep (key engagement min), plain Ø12.700 mm shank (D max), example length under the head 1.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-5-8-11x38.1mm | 5/8 socket head cap screw envelope: head Ø23.83 mm (A max 0.938 in) x 15.88 mm (H max 0.625 in), hex socket 1/2 in across flats x 0.307 in deep (key engagement min), plain Ø15.875 mm shank (D max), example length under the head 1.5 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-3-4-10x50.8mm | 3/4 socket head cap screw envelope: head Ø28.57 mm (A max 1.125 in) x 19.05 mm (H max 0.750 in), hex socket 5/8 in across flats x 0.370 in deep (key engagement min), plain Ø19.050 mm shank (D max), example length under the head 2.0 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-7-8-9x50.8mm | 7/8 socket head cap screw envelope: head Ø33.32 mm (A max 1.312 in) x 22.22 mm (H max 0.875 in), hex socket 3/4 in across flats x 0.432 in deep (key engagement min), plain Ø22.225 mm shank (D max), example length under the head 2.0 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
| shcs-1-8x50.8mm | 1 socket head cap screw envelope: head Ø38.10 mm (A max 1.500 in) x 25.40 mm (H max 1.000 in), hex socket 3/4 in across flats x 0.495 in deep (key engagement min), plain Ø25.400 mm shank (D max), example length under the head 2.0 in (Xem's choice); no thread, top chamfer, fillet or socket cone | STEP · STL |
Let your AI pull this. Add
Set it up →https://xemstudio.com/mcp to Claude, ChatGPT, Cursor or any MCP client (free, no account, one minute) and it can look up exact sizes, mating fits and free STEP/STL from every chat.Plain text: sheet.txt · JSON: /api/geometry?object=socket-head-cap-screws-inch-full
Fits with
Free
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Flat head socket cap screws, inch (ASME B18.3, 82° countersunk) #0 to 1-1/2: head, hex socket, key engagement + models #0 to 150.8×49.2×50.8 mm★ 18 filesFree
Button head socket cap screws, inch: #4-40 to 1/2-13 (ASME B18.3)9 sizes★ 25 filesFreeSocket set screws, inch (ASME B18.3), cup point: hex key size, cup and flat point diameter, shortest length #0 to 118 sizes★ sheetFreeThread size reference: UNC / UNF and ISO metric coarse / fine — major, minor and pitch diameter, tap drill, clearance hole (close, normal, loose)201 sizes★ sheetFree
Socket head cap screws, M2–M8 (ISO 4762 / DIN 912)7 sizes★ 47 filesFree
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Questions
What is the head diameter of a 1/4-20 socket head cap screw?
0.375 in max and 0.365 in min (9.53 mm), head height 0.250 in max / 0.244 in min, 3/16 in hex socket, key engagement 0.120 in min (ASME B18.3 as printed; AFT agrees).
What hex key fits a #8-32 socket head cap screw?
9/64 in (nominal hex socket size); head 0.270 in max x 0.164 in high.
What size hex key for a 5/8-11 socket head cap screw?
1/2 in; head diameter 0.938 in max, height 0.625 in max, key engagement 0.307 in min.