ASME B18.6.3 UNC Cross Recessed Flat Countersunk Machine Screws

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 Flat Countersunk 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.

Cross recessed or slotted countersunk — does the head diameter match?

Not exactly. Comparing the collected ASME B18.6.3 tables, the cross recessed countersunk head runs slightly larger than its slotted counterpart: at #6 the cross recessed table prints 0.262 in maximum head diameter against 0.252 in for the slotted table. The difference is small, but a recess sized around a slotted callout can leave a visibly proud cross recessed head, so state the drive explicitly and check the flush fit at the quoted size rather than assuming the two tables are dimension-identical.

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. Using the driver one size off is the common bench error — it cams out and reams the recess. If your assembly line standardises on one or two driver sizes, keep that in mind when consolidating gauges; the recess size follows the screw diameter, not the line preference.

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.