TX31 6-Lobe Pin TX Countersunk Thread Forming Security Screw
Countersunk head thread forming security screw for plastics (30° thread angle), M3–M6 as tabulated: head diameters 6.0–12.0 mm, tools TT10–TT30, lengths 6–80 mm with a mixed A2-stainless / zinc-steel material-coded matrix. Head height not tabulated (source row all dashes) — no head-height claim made.
Last updated: 2026-11
Specifications
TX31 is the flush-finish member of the plastics thread-forming pair: a countersunk head that seats level with the host surface, and a forming thread cut with a 30° angle that the collected page credits with slicing through plastic for maximum material engagement and the highest pull performance of the line. Like TX30 it installs into a moulded or pre-drilled hole, and the pin inside the 6-lobe recess keeps standard Torx bits out — the page even calls the drive family out for maximum-torque capability, which is how a small plastics screw resists being backed out by an ordinary toolkit. The tabulated range is M3 to M6 with head diameters 6.0–12.0 mm; the source’s head-height row is all dashes, so this page makes no head-height claim and countersink depth should be confirmed at quotation. Tool sizes are stated in the TT series (TT10–TT30), a different driver series from the TX sizes used elsewhere in this batch — worth checking against your existing bit stock before standardising. The availability matrix is material-coded per the page’s own legend: A2 stainless and zinc/black-zinc steel markers alternate cell by cell from 6 mm to 80 mm, including an M3 column where the two materials alternate between adjacent lengths — read the matrix by material before committing a drawing to one grade, because the long lengths (55–80 mm) are marked in zinc-plated steel only.
| Designation | TX31 — countersunk head thread forming security screw for plastics (30° thread angle), 6-lobe pin TX drive; flush finish in moulded or pre-drilled holes; reusable two-way security fixing |
|---|---|
| Thread range (tabulated) | M3, M3.5, M4, M4.5, M5, M6 |
| Head diameter d1 (mm) | M3 6.0 · M3.5 7.0 · M4 8.0 · M4.5 9.0 · M5 10.0 · M6 12.0 |
| Head height k | Not tabulated — the source row is all dashes; no head-height claim is made, confirm countersink depth at quotation |
| Tool size (collected) | TT10 (M3) · TT15 (M3.5) · TT20 (M4) · TT20 (M4.5) · TT25 (M5) · TT30 (M6) — TT-series tools, distinct from the TX-series sizes used on other pages in this batch |
| Length availability (as marked) | 6–80 mm material-coded matrix: A2 stainless marks M3 6/8/10/12/14/16/18/20 mm and spot pairs on M4/M5; zinc/black-zinc steel marks the rest of the envelope, including all cells from 55 mm upward (M5/M6 55–70, M6 75–80) and every cell from 22–40 mm on M3.5–M6; unmarked pairs at quotation — legend: A2 = stainless-steel marker, zinc = steel (zinc or black zinc) marker |
| Standard materials | Steel and A2 stainless steel as standard, with a range of finishes available |
Materials
- Steel, zinc or black zinc plated (per matrix marker)
- A2 stainless steel (per matrix marker)
- Other finishes to order as specials
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 (TX31 6-Lobe Pin TX Countersunk Thread Forming Security Screw) 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 does the material flip between stainless and zinc steel along the M3 column?
That is what the collected matrix marks, and this page renders it as marked rather than smoothing it: on M3, 6, 8, 10, 12, 14, 16, 18 and 20 mm carry the A2 stainless marker while 7, 9, 11, 13, 15 and 17 mm carry the zinc-steel marker. The practical reading is that stock exists in both materials on M3 but in different lengths — so a drawing that assumes one material across the board will hit gaps. Check the matrix row for your exact length, and treat unmarked pairs and mixed-material orders as quotation questions.
The tool sizes are TT, not TX — does my existing pin-TX bit fit?
Check before you assume: the collected page states TT10–TT30 for this line while the rest of the 6-lobe pin family on this site is tabulated in TX-series sizes. Both drive the same security principle, but if your maintenance tooling is standardised on TX-series insert bits, confirm compatibility or budget for the TT-series driver when you order — a security screw whose matched bit is not on the shelf is a maintenance stop, not a security feature.
What should an RFQ for TX31 state?
State the designation (TX31 countersunk thread forming for plastics), thread size and length, material per the matrix marker you need (A2 stainless or zinc/black-zinc steel), the host plastic and hole spec, countersink depth if flush finish is critical (the head-height data is not published), and the TT-series tooling situation. Long lengths — 55 mm and up — are marked zinc-plated steel only, so a stainless long screw is a special enquiry.
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