Expansion Inserts · M2 – M8
EXPANSION · HEADED
Expansion Insert
Headed
Collar on the installation face provides positive seating. Expansion fingers grip the pilot-hole wall as the bolt is driven in — no adhesive or heat required.
Thread rangeM2 – M8
Collar Ø (D)4.8 – 11.1 mm
Length (L)3.9 – 12.6 mm
Pilot hole (d₁)3.2 – 9.7 mm
MaterialCW614N brass
EXPANSION · REVERSE HEAD
Expansion Insert
Reverse Head
Collar sits on the blind side of the component. The open expansion end inserts first — ideal where a flush face is required on the visible side.
Thread rangeM2 – M8
Collar Ø (D)4.8 – 11.1 mm
Body Ø (D₁)3.2 – 9.5 mm
Length (L)3.9 – 12.6 mm
MaterialCW614N brass
EXPANSION · UNHEADED
Expansion Insert
Unheaded
No collar — flush or below-surface installation on both faces. Retained entirely by expansion within the pilot hole. Suitable where minimal projection is critical.
Thread rangeM2 – M8
Body Ø (D)3.2 – 9.5 mm
Length (L)3.9 – 12.6 mm
Pilot hole (d₁)3.2 – 9.7 mm
MaterialCW614N brass
Expansion Insert — Headed
All dimensions in mm
| Thread | D | T | L | d₁ | t₁ |
|---|---|---|---|---|---|
| M2 | 4.8 | 0.43 | 3.9 | 3.2–3.3 | 2.4 min |
| M2.5 | 5.5 | 0.51 | 4.7 | 4.0–4.1 | 3.2 min |
| M3 | 5.5 | 0.51 | 4.7 | 4.0–4.1 | 3.2 min |
| M3.5 | 6.4 | 0.66 | 6.3 | 4.8–4.9 | 3.6 min |
| M4 | 7.1 | 0.82 | 7.9 | 5.6–5.7 | 4.0 min |
| M5 | 7.9 | 1.00 | 9.4 | 6.4–6.5 | 4.8 min |
| M6 | 9.5 | 1.25 | 12.6 | 8.0–8.1 | 6.0 min |
| M8 | 11.1 | 1.25 | 12.6 | 9.6–9.7 | 7.0 min |
Expansion Insert — Reverse Head
All dimensions in mm · D₁ = body barrel diameter
| Thread | D | T | L | D₁ | d₁ | t₁ |
|---|---|---|---|---|---|---|
| M2 | 4.8 | 0.43 | 3.9 | 3.2 | 3.2–3.3 | 2.4 min |
| M2.5 | 5.5 | 0.51 | 4.7 | 4.0 | 4.0–4.1 | 3.2 min |
| M3 | 5.5 | 0.51 | 4.7 | 4.0 | 4.0–4.1 | 3.2 min |
| M3.5 | 6.4 | 0.66 | 6.3 | 4.7 | 4.8–4.9 | 3.6 min |
| M4 | 7.1 | 0.82 | 7.9 | 5.5 | 5.6–5.7 | 4.0 min |
| M5 | 7.9 | 1.00 | 9.4 | 6.3 | 6.4–6.5 | 4.8 min |
| M6 | 9.5 | 1.25 | 12.6 | 7.9 | 8.0–8.1 | 6.0 min |
| M8 | 11.1 | 1.25 | 12.6 | 9.5 | 9.6–9.7 | 7.0 min |
Expansion Insert — Unheaded
All dimensions in mm · D = body outer diameter
| Thread | D | L | d₁ | t₁ |
|---|---|---|---|---|
| M2 | 3.2 | 3.9 | 3.2–3.3 | 2.4 min |
| M2.5 | 4.0 | 4.7 | 4.0–4.1 | 3.2 min |
| M3 | 4.0 | 4.7 | 4.0–4.1 | 3.2 min |
| M3.5 | 4.7 | 6.3 | 4.8–4.9 | 3.6 min |
| M4 | 5.5 | 7.9 | 5.6–5.7 | 4.0 min |
| M5 | 6.3 | 9.4 | 6.4–6.5 | 4.8 min |
| M6 | 7.9 | 12.6 | 8.0–8.1 | 6.0 min |
| M8 | 9.5 | 12.6 | 9.6–9.7 | 7.0 min |
Threaded Inserts · M2.5 – M10
THREADED · HEADED
Threaded Insert
Headed
Knurled external body with head collar. Pressed, moulded-in, or ultrasonically installed into thermoplastics and thermosets. Internal ISO metric thread. Available M2.5–M10.
Thread rangeM2.5 – M10
Head Ø (D)6.0 – 16.0 mm
Body Ø (D₁)4.5 – 14.0 mm
Length (L)6.0 – 18.0 mm
MaterialCW614N brass
THREADED · UNHEADED
Threaded Insert
Unheaded
Fully flush installation on both faces. Knurled body bonds permanently within the plastic. Ideal for mould-in installation or blind-hole press fitting where no collar can protrude.
Thread rangeM2.5 – M10
Body Ø (D₁)4.5 – 14.0 mm
Length (L)6.0 – 18.0 mm
Pilot hole (d₂)4.0 – 12.8 mm
MaterialCW614N brass
Threaded Insert — Headed
All dimensions in mm · d₂ = thermoplastics · d₃ = thermosets
| Thread | D | T | L | D₁ | d₂ | d₃ |
|---|---|---|---|---|---|---|
| M2.5 | 6.0 | 0.58 | 6 | 4.5 | 4.0–4.1 | 4.1–4.4 |
| M3 | 6.5 | 0.58 | 6 | 5.0 | 4.5–4.6 | 4.6–4.8 |
| M3.5 | 7.5 | 0.75 | 8 | 6.0 | 5.3–5.4 | 5.5–5.7 |
| M4 | 8.0 | 0.90 | 8 | 6.5 | 5.8–5.9 | 6.0–6.2 |
| M5 | 9.5 | 1.05 | 10 | 8.0 | 7.1–7.2 | 7.3–7.6 |
| M6 | 12.0 | 1.32 | 14 | 10.0 | 8.6–8.8 | 9.0–9.4 |
| M8 | 14.0 | 1.32 | 15 | 12.0 | 10.6–10.8 | 11.0–11.4 |
| M10 | 16.0 | 1.60 | 18 | 14.0 | 12.6–12.8 | 13.0–13.4 |
Threaded Insert — Unheaded
All dimensions in mm · d₂ = thermoplastics · d₃ = thermosets
| Thread | D₁ | L | d₂ | d₃ |
|---|---|---|---|---|
| M2.5 | 4.5 | 6 | 4.0–4.1 | 4.1–4.4 |
| M3 | 5.0 | 6 | 4.5–4.6 | 4.6–4.8 |
| M3.5 | 6.0 | 8 | 5.3–5.4 | 5.5–5.7 |
| M4 | 6.5 | 8 | 5.8–5.9 | 6.0–6.2 |
| M5 | 8.0 | 10 | 7.1–7.2 | 7.3–7.6 |
| M6 | 10.0 | 14 | 8.6–8.8 | 9.0–9.4 |
| M8 | 12.0 | 15 | 10.6–10.8 | 11.0–11.4 |
| M10 | 14.0 | 18 | 12.6–12.8 | 13.0–13.4 |
Material & Properties
Alloy Specification
CW614N · CuZn39Pb3
Free-cutting brass to EN 12164. Optimised for precision CNC machining — the ~100% free-cutting machinability benchmark (with C36000). Tight dimensional control ensures consistent knurl grip and thread accuracy. CW614N datasheet →
Cu 57–59%
Pb 2.5–3.5%
Zn remainder
Mechanical Properties
Tensile Strength
380 MPa
min, EN 12164
Yield Strength
200 MPa
0.2% proof stress
Hardness
~120 HV
Vickers hardness
Machinability
~100%
free-cutting benchmark
Compliance
RoHS 3 · REACH
Compliant with EU Directive 2011/65/EU (RoHS 3) and REACH Regulation (EC) 1907/2006. No restricted substances above threshold.
RoHS Compliant
REACH OK
Standards
ISO Metric Thread
Internal threads to ISO 965-1 tolerance class 6H. Alloy to EN 12164. Dimensional data verified per Brassland internal QC standard.
ISO 965-1
EN 12164
Origin
Made in Jamnagar
Manufactured at our GIDC Phase-3 facility, Jamnagar, Gujarat — the global centre of brass precision parts. Exported to 40+ countries.
Jamnagar, India
40+ Countries
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Brass Threaded Inserts
Selection guide by installation method
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Self-Tapping & Press-In Inserts
Cold installation — incl. foam-grade types
Frequently Asked Questions
How do I choose between expansion inserts and knurled threaded inserts?
Expansion inserts install cold — the fingers grip the pilot-hole wall as the bolt is driven, so no press, heat or special equipment is needed; ideal for field assembly and thermosets. Knurled threaded inserts give higher pull-out and torque and are pressed, moulded-in or ultrasonically installed. For self-tapping, foam-grade and barbed press-in types see our cold-installation range, or start with the selection guide.
What thread sizes are available?
Standard coverage runs M2 to M10 ISO metric and #2-56 to 3/8-16 UNC, in headed, reverse-head and unheaded styles. Internal threads are produced to ISO 965-1 tolerance class 6H. Custom lengths, knurl patterns and thread sizes are made to drawing.
What material are Brassland inserts made from?
Inserts are machined from CW614N (CuZn39Pb3) free-cutting brass rod per EN 12164, RoHS and REACH compliant. Nickel, tin and zinc plating options are available on request — see our CW614N datasheet and surface finishes guide.
Can I get samples before ordering?
Yes — free samples are available for evaluation. All production is made to order; send your drawing or a competitor part number and we’ll confirm the equivalent, with pricing and lead time within one business day.
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