Chazcool M4 x 0.7 Thread Repair Kit — 50 Stainless Steel Inserts, 2D Length with Tap & Tool

Chazcool's M4 x 0.7 Thread Repair Kit supplies fifty stainless-steel M4 x 2D inserts plus the tap, installation tool, tang breaker and drill bit needed to rebuild stripped or worn M4 threads.

If fastener holes in aluminum, plastic or other low-strength materials wear out, a threaded insert restores a strong, repeatable M4 connection instead of replacing the part. These stainless-steel coil-style inserts expand the life and reliability of screw joints by evening load distribution, resisting wear and reducing the chance of thread failure when components are removed and reinstalled often.

How will these M4 inserts improve a frequently disassembled part?

The inserts provide a durable stainless-steel internal thread that resists wear far better than soft base materials. Their slight elasticity evens contact across threads, reduces micro-misalignment, and helps absorb vibration from moving assemblies.

• Stainless-steel inserts replace weak native threads for longer life.
• Elastic coil design distributes load evenly across threads.
• Reduces thread wear from repetitive assembly and disassembly.

What tools are included and what steps are required for installation?

The kit includes an M4 installation tool, an ST4 tap, a tang breaker and a drill bit, which lets you tap and install the insert into the prepared hole and then remove the tang. Basic drilling, tapping and insertion are all that’s needed—no specialty equipment.

• Use the provided drill bit to clear the damaged hole to the correct diameter.
• Tap the hole with the included ST4 tap to accept the insert body.
• Install the insert using the M4 tool and snap off the tang with the tang breaker.

Which materials and applications are these inserts suited for?

These M4 stainless inserts are designed for lower-strength substrates such as aluminum, softer alloys and many plastics where screw threads are prone to stripping. They are commonly used in enclosures, machinery panels, electronic mounts, and repair work where repeated removal is expected.

• Best for aluminum parts, light alloys and many plastics.
• Ideal for enclosures, brackets, fixtures and maintenance repairs.
• Useful wherever repeated fastening reduces thread life.

Specifications: stainless-steel material, M4 internal diameter, installed length 2D = 8 mm, quantity 50 inserts, approximate kit weight 89 g. Package includes 50 x M4 x 2D threaded inserts, 1 x M4 installation tool, 1 x ST4 tap, 1 x tang breaker and 1 x drill bit. Note: the main insert style may be shipped randomly; order only if that variability is acceptable.

Who is this for? Technicians, hobbyists and maintenance teams who need to repair or reinforce stripped M4 threads without replacing parts will find this kit especially useful. It suits anyone maintaining machinery, electronics housings, furniture or automotive trim where robust, repeatable M4 screw connections are required.