M3 x 0.5mm x 1D Helicoil Wire Inner Thread Inserts, Coiled Wire Helical Screws, 304 Stainless Steel, Metric, 80Pcs

Sold as 1.5D, but only has 7 full threads. With a 1.5mm pitch that puts it at 10.5mm in length, which is just barely over the 10mm expected of a 1D thread insert. They work otherwise, but I didn't specifically pick a 1.5D thread insert just for giggles, I needed those extra 3 threads. The product specs and images are a lie, so whether or not it's intentional that earns it an instant 1 star. (In the image it shows even smaller than 10.5mm in length, but the threads are stretched a bit during installation)

We use these for our laser cut acrylic projects for when we need screws in to the plastic. These always work

Good product.

Used these M3×0.5 (1D) coils to fix stripped threads on an aluminum bracket and a 3D-printer part. The coils are consistent, no burrs, and standard M3 screws run in smooth with zero wobble. Tangs snapped cleanly with a punch. Once installed, the threads feel stronger than the originals. Tips: you’ll need the proper M3×0.5 STI tap and about a 3.2 mm drill. A dab of blue Loctite on the outside of the coil keeps it put. 1D length is perfect for shallow holes; if you need more engagement, look for 1.5D/2D.

Work great held up great.