The self-tapping insert carries a sharp external cutting thread interrupted by three equidistant longitudinal flutes. As it is driven into a pilot hole, the flutes shear a clean mating thread in the surrounding plastic and channel the displaced material away — much like a tap. No heat or ultrasonic energy is required, so installation needs only a screwdriver or simple insertion spindle.
Because the insert cuts rather than melts, installation torque rises predictably to a defined seating value; monitoring this torque confirms full thread engagement on the production line. The internal thread (d) is cut to ISO 6H tolerance and the body length (L) sets the depth of engagement. Headed, reduced-head, regular-head and double-ended variants suit flush, recessed or through-fix applications.
Self-tapping inserts are the preferred choice for harder engineering thermoplastics (ABS, Nylon, PC, glass-filled grades) and for field service where heat-set tooling is unavailable.
| Thread | Pitch (mm) | External Ø (B) | Length L (mm) | Rec. hole Ø | Min boss Ø | Min wall |
|---|---|---|---|---|---|---|
| M2 | 0.40 | 3.50 | 4.0 – 4.8 | 3.1 – 3.3 | 5.8 | 1.25 |
| M2.5 | 0.45 | 4.33 | 4.0 – 6.25 | 3.8 – 4.1 | 7.2 | 1.55 |
| M3 | 0.50 | 4.73 | 4.0 – 6.25 | 4.1 – 4.4 | 7.7 | 1.65 |
| M3.5 | 0.60 | 5.52 | 5.0 – 7.3 | 5.0 – 5.3 | 9.3 | 2.00 |
| M4 | 0.70 | 6.31 | 5.6 – 8.4 | 5.8 – 6.1 | 10.7 | 2.30 |
| M5 | 0.80 | 7.50 | 6.4 – 10.0 | 6.9 – 7.2 | 12.6 | 2.70 |
| M6 | 1.00 | 8.69 | 7.9 – 12.0 | 8.0 – 8.4 | 14.7 | 3.15 |
| M8 | 1.25 | 11.06 | 9.5 – 12.4 | 10.1 – 10.6 | 18.6 | 4.00 |
| M10 | 1.50 | 13.95 | 12.0 – 16.0 | 13.0 – 13.5 | 23.7 | 5.10 |
Dimensions for the self-tapping insert range. B = external thread diameter; L spans the short/regular/long length options. Recommended hole diameter is for thermoplastics; confirm against substrate and drawing at quotation. Reduced-head and double-ended variants available across the range.
The barbed press-in insert has an external profile of opposed barbs and a diamond knurl that resist both pull-out (axial) and spin-out (torque). The same part can be installed three ways: pressed cold into a pre-moulded hole, set with a heated tip, or driven by an ultrasonic horn. With heat or ultrasonic energy the surrounding plastic softens, flows into the barbs and knurl, and re-solidifies to lock the insert permanently — the highest-performing method.
Key dimensions are the internal thread (d), the head/flange diameter (D) where fitted, overall length (L) and the recommended hole diameter. A square lead-in chamfer at each end aids automatic feeding and starts the insert straight. Unheaded, single-head, double-head and thin-section variants cover flush, blind and tight-pitch boss layouts.
Barbed press-in inserts suit softer thermoplastics, foamed grades and over-moulded assemblies, and are the standard choice for high-volume heat-set lines in consumer electronics, automotive trim and enclosures.
| Thread | Pitch (mm) | Length L (mm) | Rec. hole Ø | Min boss Ø | Min wall |
|---|---|---|---|---|---|
| M1.6 | 0.35 | 3.2 | 2.3 – 2.5 | 4.5 | 1.00 |
| M2 | 0.40 | 3.1 – 4.8 | 3.0 – 3.3 | 6.0 | 1.35 |
| M2.5 | 0.45 | 4.1 – 5.2 | 3.7 – 4.0 | 7.4 | 1.70 |
| M3 | 0.50 | 4.1 – 5.2 | 3.7 – 4.0 | 7.4 | 1.70 |
| M3.5 | 0.60 | 4.1 – 7.0 | 4.6 – 5.0 | 9.5 | 2.25 |
| M4 | 0.70 | 5.6 – 8.5 | 5.4 – 5.9 | 10.9 | 2.50 |
| M5 | 0.80 | 6.6 – 10.1 | 6.0 – 6.5 | 12.2 | 2.85 |
| M6 | 1.00 | 7.7 – 12.3 | 7.7 – 8.2 | 14.6 | 3.20 |
| M8 | 1.25 | 8.3 – 13.8 | 10.2 – 10.6 | 19.1 | 4.25 |
| M10 | 1.50 | 10.5 – 16.1 | 12.5 – 13.0 | 23.2 | 5.10 |
| M12 | 1.75 | 16.1 | 15.0 – 15.4 | 25.8 | 5.20 |
Dimensions for the barbed press-in insert range (unheaded / single- & double-thickness head variants). L spans short and regular lengths. Recommended hole diameter is for cold press / heat-set in thermoplastics; open up slightly for glass-filled grades. Thin-section variants available for tight boss walls.
Foam-grade inserts use a coarse, truncated external thread with a pitch up to 2.5 times that of a standard insert. The deep, widely-spaced flights capture a large volume of substrate between turns, spreading load over a big surface and dramatically increasing pull-out strength in soft, low-density materials where a fine thread would simply strip or pull through.
They are designed for structural foam mouldings, MDF, chipboard, particleboard and laminated panels — common in furniture, point-of-sale fixtures, loudspeaker enclosures and lightweight composite cores. The insert is screwed in (or moulded in) and provides a clean ISO 6H metal thread (d) for repeated assembly and disassembly. Headed and double-ended variants distribute clamp load and allow through-panel fixing.
Where the substrate is extremely friable, foam-grade inserts can be combined with a bonding adhesive for permanent retention.
| Thread | Coarse ext. pitch | External Ø (B) | Length L (mm) | Rec. hole Ø | Min boss Ø | Min wall |
|---|---|---|---|---|---|---|
| M2.5 | 1.81 | 5.50 | 8.0 | 4.25 – 5.00 | 12.50 | 3.75 |
| M3 | 1.81 | 5.50 | 8.0 – 9.0 | 4.25 – 5.00 | 12.50 | 3.75 |
| M3.5 | 2.12 | 6.30 | 8.5 | 5.00 – 5.75 | 14.40 | 4.33 |
| M4 | 2.31 | 7.10 | 9.0 – 11.0 | 5.70 – 6.50 | 16.30 | 4.90 |
| M5 | 2.54 | 8.70 | 10.0 – 12.0 | 7.20 – 8.10 | 20.30 | 6.10 |
| M6 | 2.82 | 10.00 | 12.0 – 16.0 | 8.40 – 9.30 | 23.30 | 7.00 |
| M8 | 3.63 | 12.00 | 16.0 – 20.0 | 10.40 – 11.30 | 28.30 | 8.50 |
Dimensions for the foam-grade insert range. Note the coarse truncated external pitch (e.g. 1.81 mm at M2.5) versus a standard self-tapping insert — this is what grips low-density foam, MDF and chipboard. L spans double-ended and reduced-headed length options. Recommended hole diameter depends on substrate density; confirm against drawing at quotation.
Each insert family is produced in a full set of head, length and body configurations to suit flush, recessed, blind and through-fix layouts — and Brassland routinely manufactures every variant shown below in CW614N brass. Beyond the standard range, we make fully bespoke inserts to your drawing: any thread, length, knurl or barb profile, head form, alloy or plating.
Non-standard thread sizes, special lengths, bespoke knurl or barb profiles, unique head forms, UNC/UNF threads, alternative alloys and platings — if you can draw it, we can turn it. Send a PDF or dimensioned sketch and we will quote within 24 hours from Jamnagar.
Brassland does not hold stock. All self-tapping, press-in and foam-grade inserts are machined and knurled to order from CW614N brass bar in our Jamnagar facility. This means every batch is fresh, fully traceable from bar to finished part, and can be supplied to your exact thread size, length and quantity without compromise on quality.
Heat-set and barbed press-in inserts give moulded plastic housings a durable, reusable metal thread for screw-fixed covers, PCB standoffs, battery doors and connector panels. The brass insert survives repeated opening that would strip a self-tapping screw straight into plastic. Electronics components →
Self-tapping and press-in inserts anchor trim, brackets, sensor housings and under-bonnet mouldings. Their high pull-out and anti-spin knurl resist vibration and thermal cycling, making them a standard fastening for engineering-plastic and composite components. Automotive components →
Foam-grade inserts provide strong, demountable threads in MDF, chipboard, structural foam and laminated panels — used in flat-pack furniture, point-of-sale fixtures, loudspeaker cabinets and lightweight composite cores where conventional inserts pull through.
Self-tapping inserts have an external cutting thread and tap their own thread into the plastic — installed cold, no heat. Barbed press-in inserts have a barbed, knurled body and are pressed, heat-set or ultrasonically installed so the substrate flows around the profile for maximum pull-out. Foam-grade inserts use a coarse truncated thread (up to 2.5× standard pitch) to grip soft substrates such as structural foam, MDF and chipboard without pulling through.
Not always. Self-tapping inserts install cold — simply driven in with a screwdriver or insertion tool. Barbed press-in inserts can be pressed cold, or set with heat / ultrasonic for the highest pull-out. Heat-set inserts are designed specifically for a heated press tip or ultrasonic welder, where molten plastic flows into the knurl and re-solidifies to lock the insert.
Self-tapping: M2–M10. Barbed press-in: M1.6–M12. Foam-grade: M2.5–M8. Heat-set and moulding inserts: M2–M12. Internal threads are cut to ISO 6H tolerance. Non-standard threads, lengths and unified (UNC/UNF) forms are available on request.
Standard Brassland threaded inserts are manufactured in CW614N (CuZn39Pb3) free-machining brass to EN 12164. This high-lead alpha-beta brass machines and knurls cleanly, giving sharp cutting flutes and crisp retention knurls. It is RoHS compliant under exemption 6(c) and REACH-declared. Other alloys and platings (nickel, tin) are available on request.
Yes. CW614N brass contains ~3% lead which is explicitly exempted under RoHS Annex III entry 6(c) (valid to 30 June 2027). REACH Article 33 SVHC disclosures are supplied with each order. Mill test certificates per EN 10204 Type 3.1 are standard; Type 3.2 (third-party witness) is available on request.
All Brassland inserts are machined to order from CW614N bar stock in Jamnagar — there is no pre-held inventory, which is what keeps every batch traceable from bar to finished part. Standard lead time is 3–5 weeks from an approved drawing, with prototype and sample quantities sooner. There is no strict minimum order quantity; first orders are typically placed from around 1,000 pieces. Send a drawing through the quotation page and we will come back, usually within 24 hours.
Yes — made-to-drawing is the normal case here rather than the exception, because nothing is held in stock. Send a PDF, STEP file or dimensioned sketch showing thread, external profile, length, knurl or barb form, alloy and finish, and we will quote it, typically within 24 hours. Non-standard threads, UNC/UNF forms, special lengths and alternative alloys or platings are routine work.
Yes. Prototype and sample batches are run ahead of the production order and ship sooner than the standard 3–5 week lead time. Samples come off the same machines and the same certified bar lot as production parts and carry the same EN 10204 Type 3.1 mill certificate and dimensional inspection report, so what you approve is what you go on to receive.
Each shipment is released with an EN 10204 Type 3.1 mill certificate for the brass it was machined from; Type 3.2 with third-party witness is available on request. A Certificate of Conformity and a dimensional inspection report covering the drawing's controlled features travel with the consignment, and RoHS and REACH statements are issued alongside, with SVHC disclosure on request. Brassland is ISO 9001:2015, ISO 14001:2015 and ISO 45001:2018 certified by DQS.
We quote on Incoterms 2020: DDP, FOB and CIF are standard, and EXW or DAP can be arranged on request. Consignments leave through Mundra, Pipavav, Kandla or Nhava Sheva depending on routing, and brass inserts and related turned components are declared under HS codes 7415, 7412 and 7419. Brassland is a Star Export House recognised by the Government of India and ships to customers in more than 40 countries.
Brassland manufactures to the published EN, ISO and ASTM specifications below. Mill certificates per EN 10204 Type 3.1 are supplied as standard; Type 3.2 (third-party witnessed) available on request. Open any link to verify the standard directly with the publishing body.
Last reviewed: May 2026. All Brassland products are made to order — please confirm grade, surface finish, plating and packaging requirements at quotation stage. Standards listed above are referenced; production lots are released against the EN 10204 Type 3.1 inspection certificate accompanying each shipment.