SB08 Hex Head Barrel Nuts (Hex Sleeve Nuts)
Imperial hex head barrel nuts (sex bolts): internally threaded, smooth-barrel sleeves under a standard hexagon head, 5/16"–1/2" barrel diameters with 10-24 to 3/8"-16 threads. High-torque spanner installation, stainless steel.
Last updated: 2026-11
Specifications
The hex head barrel nut — also sold as a hex sleeve nut or hexagon head sex bolt — is the high-torque end of the family: a female, internally threaded barrel with a smooth, serration-free barrel under a standard hexagon head that a spanner or socket drives to full torque. The collected tabulation is imperial: 5/16" barrels threaded 10-24 with heads 1/2" across flats; 3/8" barrels threaded 1/4"-20 with 5/8" heads; and 1/2" barrels threaded 3/8"-16 with 3/4" heads — barrel lengths from 1/2" up to 1" and thread depths of 5/16" to 3/8", head heights 3/16" to 1/4". Stainless steel is the collected material, in three barrel diameters with 3/4" and 1" lengths tabulated per diameter. Because the hex head takes genuine wrench torque while the smooth barrel supports the clamped components without biting them, the pattern suits structural-ish panel and timber sandwich joints — workbenches, framing, equipment tables — where a conventional nut-and-bolt would either protrude or chew the face.
| Designation | SB08 — hex head barrel nut (hex sleeve nut; hexagon head sex bolt), smooth barrel, no serrations |
|---|---|
| Barrel diameters (tabulated) | 5/16", 3/8", 1/2" |
| Thread per barrel diameter | 5/16" → 10-24 · 3/8" → 1/4"-20 · 1/2" → 3/8"-16 |
| Across flats per barrel diameter | 5/16" → 1/2" · 3/8" → 5/8" · 1/2" → 3/4" |
| Head height per barrel diameter | 5/16" → 3/16" · 3/8" → 13/64" · 1/2" → 1/4" |
| Barrel lengths (tabulated per diameter) | 5/16": 1/2", 3/4", 1" · 3/8": 1/2", 3/4", 1" · 1/2": 1/2", 3/4", 1" |
| Thread depth (tabulated) | 5/16" barrels: 5/16" · 3/8" and 1/2" barrels: 3/8" |
| Material (collected legend) | Stainless steel |
| Installation | Standard spanner or socket — high torque; barrel supports the fixing without serrations |
Materials
- Stainless steel
Ordering & documentation
Documents
Shipments are backed by Mill Test Certificate (MTC), Dimensional Report, Salt Spray Test Report on request, with full batch traceability from raw material to finished product. Quality management follows the owner-confirmed compliance list: ISO 9001:2015, RoHS, REACH. Exact document sets are confirmed on the order.
Quotation
- The fastener family (SB08 Hex Head Barrel Nuts (Hex Sleeve Nuts)) plus the standard designation from your drawing — DIN / ISO / JIS / ASTM / ANSI, or a drawing for custom parts.
- Size (diameter and length), thread type (metric or inch), property class or grade, and coating or finish.
- Quantity per size and your target delivery date.
- Destination country, and any required documents (for example a mill test certificate) so the quote includes them.
Sample & supply
Minimum order quantity is 10,000 pieces. Stock items run 3–7 days. Quantities or variants outside the standard range are confirmed at quotation.
Storage & shipping
Parts are packed for export and shipped factory-direct to buyers in Europe, Asia, the Americas and the Middle East. Store fasteners dry and protected until installation, and keep coated parts in their packaging until use; specific packing and preservation requirements can be stated on the order and confirmed at quotation.
Frequently asked questions
Why a smooth barrel instead of serrations under the head?
Because the barrel is the clamp face, not the head. A serrated flange bites the material to resist rotation, but on a sex bolt the hex head does the turning and the smooth barrel should slide or bear cleanly against the clamped face — no marring of finished timber, panel or laminate. Rotation is resisted by the wrench torque at the head, so the joint keeps both high clamping force and an undamaged surface.
Which thread goes with which barrel diameter?
In the collected tabulation the pairing is fixed: the 5/16" barrel carries a 10-24 thread with a 1/2" hex head, the 3/8" barrel carries 1/4"-20 with a 5/8" head, and the 1/2" barrel carries 3/8"-16 with a 3/4" head — each available in 1/2", 3/4" and 1" barrel lengths. Pick the barrel diameter for the grip you need, and the thread and head follow.
What is the MOQ and lead time for this nut type?
The minimum order quantity is 10,000 pieces. Stock items ship in 3–7 days; non-stock items are confirmed at quotation. Common diameters in this nut type are widely stocked; confirm the exact schedule against quantity and size mix at quotation.
What should an RFQ for this nut type state?
State the designation (for example the barrel-nut SKU and head style), nominal thread size and pitch, overall barrel length or grip, material and finish (plain, zinc, or stainless where compatible), whether a through-hole or blind (closed) end barrel is required, the mating screw specification, required certificates, and quantity per size — plus destination country.
Request a Quote
Get factory-direct pricing from the manufacturer.
What to include in your inquiry
- ✓ Standard and property class (e.g. DIN 912, ISO 4762, class 8.8) — or a drawing for custom parts.
- ✓ Sizes, lengths and thread type (metric or inch).
- ✓ Quantity per size and your target delivery date.
- ✓ Destination country, plus any coating or finish requirement.
- ✓ Any documents you need with the shipment (e.g. mill test certificate) so the quote includes them.
- ✓ Your inquiry goes straight to the factory team by email and gets a reply within 24 hours.
- ✓ Factory-direct pricing
- ✓ Standard and custom specifications
- ✓ Factory-direct export to buyers in Europe, Asia, the Americas and the Middle East
- ✓ Full fastener family support