CountedHex M3 Builder Hardware Kit – 630 Pieces

The CountedHex M3 Builder Hardware Kit is a practical workbench kit for 3D printer modifications, printed-part assemblies, extrusion accessories, and general maker projects.

Instead of sorting through a mixed box of hardware, you get 630 pieces across 24 separate specifications, with each specification counted and packed in its own labeled bag.

The kit is centered around commonly used M3 hardware and includes socket head, button head, and countersunk screws, plus nuts, washers, brass heat-set inserts, and 2020 extrusion T-nuts. A small selection of M2, M4, and M5 hardware is also included for common supporting tasks.

Built for the workbench

This kit is designed for builders who regularly work with printed parts, brackets, covers, mounts, and aluminum extrusion accessories.

It gives you a useful range of M3 screw lengths from 6 mm to 40 mm, along with several head styles and commonly paired hardware, so you can handle many small builds and modifications without sourcing every fastener separately.

This is a general-purpose builder kit, not a complete hardware BOM for any specific printer or machine. Always compare the included specifications with your project requirements before ordering.

Kit Contents

Item	Specification	Qty
Socket Head Cap Screw	M3 × 6 mm	25
Socket Head Cap Screw	M3 × 8 mm	80
Socket Head Cap Screw	M3 × 10 mm	20
Socket Head Cap Screw	M3 × 12 mm	30
Socket Head Cap Screw	M3 × 16 mm	20
Socket Head Cap Screw	M3 × 20 mm	20
Socket Head Cap Screw	M3 × 25 mm	15
Socket Head Cap Screw	M3 × 30 mm	20
Socket Head Cap Screw	M3 × 35 mm	10
Socket Head Cap Screw	M3 × 40 mm	15
Button Head Socket Screw	M3 × 6 mm	25
Button Head Socket Screw	M3 × 8 mm	20
Button Head Socket Screw	M3 × 10 mm	10
Countersunk Socket Screw	M3 × 6 mm	20
Countersunk Socket Screw	M3 × 10 mm	10
Hex Nut	M3, ISO 4032	50
Flat Washer	M3, DIN 125A	20
Brass Heat-Set Insert	M3 × 5 × 4 mm	80
Roll-In T-Nut with Spring Ball	M3, for compatible 2020 extrusion	50
Hammer-Head T-Nut	M3, for compatible 2020 extrusion	30
Self-Tapping Screw	M2 × 10 mm	20
Button Head Socket Screw	M4 × 6 mm	10
Button Head Socket Screw	M5 × 10 mm	15
Roll-In T-Nut with Spring Ball	M5, for compatible 2020 extrusion	15

Total: 630 pieces

Materials & Specifications

• Screws, hex nuts and washers: 304 stainless steel
• Heat-set inserts: Brass, M3 internal thread, 5 mm nominal outside diameter × 4 mm length
• T-nuts: Nickel-plated carbon steel
• Machine screw threads: Metric coarse
• Drive: Hex socket for SHCS, BHCS and FHCS machine screws

Compatibility Notes

This kit is intended as a general hardware supply for maker projects rather than a machine-specific fastener set.

• Check screw diameter, length, head style, and required quantity against your project before use.
• Heat-set insert compatibility depends on the insert pocket dimensions in your printed part. The included inserts are M3 × 5 × 4 mm.
• T-nut fit depends on the slot geometry of your 2020 aluminum extrusion. Not every 2020 extrusion profile accepts the same style of T-nut.
• The included M2, M4, and M5 hardware is supplementary and is not intended to provide a complete hardware set in those sizes.

What's Not Included

• Printed parts
• Aluminum extrusion
• Linear rails, belts, or motion components
• Electronics
• Hex keys or other installation tools
• Heat-set insert installation tools

Organized by Specification

The kit is packed in 24 separate bags, one for each listed specification. Screw head styles are kept separate even when the diameter and length are similar.

Each bag is labeled with the hardware specification and quantity, making it easier to identify parts and keep your workbench organized.

A printed packing list is included for quick reference.