Low Head Socket Cap Screws
Minimal head height for tight spaces and low-profile fastening.
For counterbores with limited depth and applications where clearance is critical.
Specifications & technical data.
Low head socket cap screws to ASME B18.3 — about half the head height of a standard socket cap, for shallow counterbores and clearance-starved assemblies.
Download our low head cap screw dimensioning table (PDF)
| Nominal Size (Basic Screw Diameter) | D | A | H | C | J | T | K | ||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Body Diameter | Head Diameter | Head Height | Max. Chamfer or Radius | Nominal Hexagon Socket Size | Minimum Key Engagement | Max. Chamfer or Radius | |||||
| Max. | Min. | Max. | Min. | Max. | Min. | ||||||
| #4 | 0.1120 | 0.108 | 0.183 | 0.176 | 0.059 | 0.053 | 0.009 | – | 0.050 | 0.038 | 0.008 |
| #5 | 0.1250 | 0.120 | 0.205 | 0.198 | 0.065 | 0.059 | 0.012 | 1/16 | 0.062 | 0.044 | 0.008 |
| #6 | 0.1380 | 0.133 | 0.226 | 0.218 | 0.072 | 0.066 | 0.013 | 1/16 | 0.062 | 0.050 | 0.008 |
| #8 | 0.1640 | 0.159 | 0.270 | 0.262 | 0.085 | 0.079 | 0.014 | 5/64 | 0.078 | 0.060 | 0.008 |
| #10 | 0.1900 | 0.184 | 0.312 | 0.303 | 0.098 | 0.092 | 0.018 | 3/32 | 0.094 | 0.072 | 0.008 |
| 1/4" | 0.2500 | 0.244 | 0.375 | 0.365 | 0.127 | 0.121 | 0.025 | 1/8 | 0.125 | 0.094 | 0.010 |
| 5/16" | 0.3125 | 0.305 | 0.437 | 0.431 | 0.158 | 0.152 | 0.033 | 5/32 | 0.156 | 0.110 | 0.010 |
| 3/8" | 0.3750 | 0.368 | 0.562 | 0.550 | 0.192 | 0.182 | 0.040 | 3/16 | 0.188 | 0.115 | 0.010 |
| 7/16" | 0.4375 | 0.429 | 0.625 | 0.618 | 0.223 | 0.213 | 0.047 | 7/32 | 0.219 | 0.135 | 0.015 |
| 1/2" | 0.5000 | 0.492 | 0.750 | 0.743 | 0.254 | 0.244 | 0.055 | 1/4 | 0.250 | 0.151 | 0.015 |
| 5/8" | 0.6250 | 0.616 | 0.875 | 0.867 | 0.316 | 0.306 | 0.070 | 5/16 | 0.312 | 0.250 | 0.015 |
All dimensions in inches, per ASME B18.3. Head height is roughly half a standard socket head cap screw. Confirm requirements with our estimating team.
Standards.
What are low head socket cap screws?
A low head cap screw trades head height for clearance: the head stands at roughly half the height of a standard socket head cap screw, with a correspondingly smaller socket. Where the counterbore is shallow or the stack-up is tight, it is the socket screw that fits.
- Roughly half standard head height
- Smaller hex socket than a standard SHCS — mind the key size
- #4 through 5/8″ per B18.3
- Alloy and stainless as standard
Other names
- Low profile socket screws
- Reduced head cap screws
- Thin head socket screws
Tips for purchasing
- Lower head = less key engagement — torque limits sit below a standard SHCS of the same size.
- Check the socket size in the table; it is one step down from standard.
- Use where clearance drives the design, not where maximum preload does.
- Certs and traceability on request.
Materials.
Representative capabilities — every item is manufactured or certified to your specification. Confirm requirements with our estimating team.
