ASME B18.6.3 UNC Cross Recessed Pan Head Machine Screws
Cross recessed (Phillips) pan head machine screws per ASME B18.6.3, UNC thread — #1 through 3/8 in basic diameter in steel or stainless steel. The low, wide domed general-purpose head of inch-series small machinery, driven by a Phillips driver.
Last updated: 2026-11
Specifications
The pan head is the workhorse of the inch machine screw line, and the cross recessed version is its production form: the same low, wide dome with a flat top and a generous bearing circle, driven by a Phillips recess that stays engaged under powered drivers. The collected ASME B18.6.3 table runs from #1 (0.0730 in basic diameter) through 3/8 in on UNC threads per inch — 40 TPI at #4, 24 at #10, 20 at 1/4, 16 at 3/8 — with head diameter and Phillips drive size per gauge: drive #1 at #3 and #4, #2 at #5 through #10, #3 at #12 through 1/4, #4 at 5/16 and 3/8. At #10 the head measures 0.373 in maximum diameter; at 1/4, 0.492 in — roughly one diameter across, the proportion that makes pan heads predictable to design around. Against the slotted pan head of the same standard, the collected tables print essentially the same head envelope; the drive is what differs, and the cross recess earns its place wherever drivers are powered. Its metric counterpart is the DIN 7985 cross recessed pan head. For the flush alternative, see the cross recessed flat countersunk page; for the widest bearing circle in the family, the truss head page.
| Standard | ASME B18.6.3 — cross recessed pan head machine screws, UNC (unified coarse) thread |
|---|---|
| Size range | #1 (0.0730 in) – 3/8 in (0.3750 in) basic diameter, UNC threads per inch; UNF counterparts in the same gauges |
| Dimensions at #3 (#3-48) | dk (head diameter) max 0.193 in; cross recess drive size #1 |
| Dimensions at #10 (#10-24) | dk max 0.373 in; cross recess drive size #2 |
| Dimensions at 1/4 (1/4-20) | dk max 0.492 in; cross recess drive size #3 |
| Dimensions at 3/8 (3/8-16) | dk max 0.740 in; cross recess drive size #4 |
| Materials | Steel, stainless steel — grade and finish confirmed at quotation (tenant supply range) |
Materials
- Steel
- 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 (ASME B18.6.3 UNC Cross Recessed Pan Head Machine Screws) 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
Pan head cross recessed against the slotted pan head — what changes?
The head envelope barely moves: the collected slotted pan head table prints 0.373 in maximum head diameter at #10 and 0.492 in at 1/4, and the cross recessed table prints the same figures. What changes is the driving: the cross recess centres a Phillips driver and holds engagement under powered assembly, while the slot tolerates a flat blade, overpainted heads and rework. Choose by how the joint is driven in service, and state the drive explicitly on the RFQ — a slotted callout filled with Phillips drivers is the classic bench error.
Which Phillips driver does each gauge take?
The collected ASME B18.6.3 table assigns the cross recess size by gauge: drive #1 at #3 and #4, #2 from #5 through #10, #3 from #12 through 1/4, and #4 at 5/16 and 3/8. The recess size follows the screw diameter — consolidating gauges on a line does not consolidate driver sizes. Driver size, gauge and length are the three fields to state explicitly on every cross recessed RFQ.
What is the MOQ and lead time for these cross recessed inch machine screws?
Minimum order quantity is 10,000 pieces per item. Stocked sizes ship in 3-7 days; non-stock gauge sizes, lengths or finishes are quoted with a confirmed schedule. Confirm the exact schedule against quantity and size mix at quotation.
What should an RFQ for these cross recessed machine screws state?
State the standard designation (ASME B18.6.3), gauge size and threads per inch (for example #6-32, #10-24, 1/4-20 UNC), length, head style, drive (cross recessed / Phillips), material and grade (steel or stainless; state the stainless grade such as 18-8/A2 or 316/A4 if specified), finish, required certificates such as a mill test report per EN 10204 3.1, and quantity per size — plus destination country.
Related knowledge
- Thread-Forming vs Thread-Cutting vs Thread-Rolling Self-Tapping Screws: What the Evidence Settles on Base Material
- Screw Family Selection by Base Material: Wood, Machine and Self-Tapping Threads, Engagement and Coating
- Hex Bolts vs Socket Head Cap Screws: What the Evidence Settles on Strength, Clearance and Cost
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