Class 5 Interference-Fit Threads

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 (Class 5 Interference-Fit Threads) 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.

When would I order a Class 5 interference-fit thread instead of a standard 2A/2B clearance fit?

When the joint must not loosen and cannot carry a locking element. A Class 5 thread drives with a torque wrench (the table gives the expected seating torque per size) and grips by pitch-diameter interference — permanently, which is why it suits studs and plugs screwed once into a housing: walk-in studs for aluminium housings, pipe plugs, fitting bosses. A 2A/2B fit assembles by hand or wrench with clearance and stays tight only through friction of the clamped joint or a lock feature. The costs of Class 5: assembly needs controlled torque, removal tends to damage the threads, and the tapped hole needs the deeper T h minimum the table lists — more for the nonferrous-except-brass column. If your drawing says "Class 5" with a size like 0.5000-13, take the interference limits and depths from the table here and confirm supply of the mating stud or tap per RFQ.

Why do the nonferrous engagement and torque values differ from the brass/ferrous columns?

Because grip has to be developed in the softer material. The interference on pitch diameter is fixed per size, but how deep the male thread must go — and how much torque that drive takes — depends on the housing: the nonferrous-except-brass column runs substantially longer engagements (T s 1.375 + .192 − 0 vs 0.750 + .192 − 0 at 1/2-13) so the interference has enough threaded length to bite into material that yields more readily, and the tapped-hole minimum T h follows it up. The torque column, by contrast, is printed for ferrous material at 1-1/4 D engagement only — the collected page does not tabulate a torque value for the nonferrous group, so do not reuse the lb-ft figures for aluminium or brass housings; treat them as ferrous-column values and confirm the seating torque for your housing material at RFQ.