Socket Head Cap Screw ASME B18.3
ASME B18.3 (Current)
- Material
- Alloy Steel
- Finish
- Blackened, Plain
- Size range
- #6-32UNC, #8-32UNC, #10-24UNC + 6 more
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Select sizes and quantities — 123 confirmed sizes to ASME B18.3
Material
Finish
| dNominal Diameter (in) | lLength (in) | sHex Socket Size (in) | dkHead Diameter (in) | kNominal Head Height (in) | dBasic Major Diameter (in) | MOQ | Quantity and inquiry |
|---|---|---|---|---|---|---|---|
| 3/8-16 UNC | 0.875 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 1 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 1.125 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 1.25 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 1.375 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 1.5 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 1.75 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 2 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 2.25 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 2.5 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 2.75 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 3 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 3.25 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 3.5 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 3/8-16 UNC | 3.75 | 0.312 | 0.562 | 0.375 | 0.375 | 2000 | |
| 1/2-13 UNC | 1 | 0.375 | 0.75 | 0.5 | 0.5 | 1500 |
Showing 16 of 123 sizes
dNominal Diameter (in)3/8-16 UNC
lLength (in)0.875
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 1 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)1
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 1.125 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)1.125
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 1.25 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)1.25
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 1.375 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)1.375
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 1.5 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)1.5
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 1.75 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)1.75
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 2 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)2
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 2.25 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)2.25
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 2.5 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)2.5
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 2.75 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)2.75
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 3 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)3
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 3.25 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)3.25
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 3.5 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)3.5
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
3/8-16 UNC × 3.75 × 0.312 × 0.562 × 0.375 × 0.375 × 16 × UNC × 3A × 0.375 × 0.3678 × 0.54 × 0.368 × 0.04 × 0.182 × 0.143 × 0.01
dNominal Diameter (in)3/8-16 UNC
lLength (in)3.75
sHex Socket Size (in)0.312
dkHead Diameter (in)0.562
kNominal Head Height (in)0.375
dBasic Major Diameter (in)0.375
MOQ2000
1/2-13 UNC × 1 × 0.375 × 0.75 × 0.5 × 0.5 × 13 × UNC × 3A × 0.5 × 0.4919 × 0.725 × 0.492 × 0.055 × 0.245 × 0.19 × 0.015
dNominal Diameter (in)1/2-13 UNC
lLength (in)1
sHex Socket Size (in)0.375
dkHead Diameter (in)0.75
kNominal Head Height (in)0.5
dBasic Major Diameter (in)0.5
MOQ1500
Product details
- Description
- Hexagon socket head cap screw manufactured to ASME B18.3. The cylindrical head has a hexagon socket drive and is seated in a counterbored hole. Threads are UNC series, class 3A, with sizes from #6-32 to 3/4-10. Material is alloy steel, supplied with blackened or plain finish. Minimum order quantities vary by diameter. For quotation, specify diameter, thread series, length, finish, and required quantity.
- Features
- Cylindrical head with hexagon socket drive for internal wrenching · Threaded to UNC class 3A over the full length up to the head · Available in diameters from #6-32 to 3/4-10 · Supplied in alloy steel with blackened or plain finish
- Applications
- Machine tool and jig assembly, Compact joints where a counterbored seat is used, Automation and equipment frames, Mould and die assembly
Order assurance
Confirmed for the quoted product and order.Reports & inspection
Agreed in the quotation.
- EN 10204 3.1 material certificate
- Dimensional inspection report
- Certificate of conformity
- Mechanical test report
- Chemical analysis report
- Coating inspection report
- Batch and lot traceability
Packaging & delivery
Options we supply.
- Bulk carton packing
- Small boxes with outer cartons
- Palletized shipment
- Fumigation-free pallets
- Inner poly bags
- Buyer branding and labels
Product questions
What sizes of Socket Head Cap Screw ASME B18.3 do you supply?
Execution standard: ASME B18.3. The confirmed specification table covers 1–10 diameters and 0.25–4.5 lengths. Use the specification table to select the exact variant required for quotation.
Which materials, grades and finishes can I order?
Material: Alloy Steel; Finish: Blackened, Plain. Availability should be confirmed against the selected specification and order quantity.
Where are these cap screws typically used?
Typical applications include Machine tool and jig assembly, Compact joints where a counterbored seat is used, Automation and equipment frames, Mould and die assembly. Final suitability depends on the selected material, grade, finish and operating conditions.







