300 Pcs M3 Threaded Inserts M3 x D5 x L4 Heat Set Inserts Brass 3D Printing Knurled Metric Nuts for Plastic, 3D Printing Components

Awesome inserts, work very well in 3D prints

A friend said he finds metric size bolts to be cheaper than the Imperial sizes. He is definitely right. I am shifting some of my 1/4 inch sizing to M6 but there are times you need the added strength that 1/4 bolts provide. That being said, I have both 1/4 inch and M6 bolts/machine screws so I am happy to have these inserts as well.

low price and work great for what i need

I've been cranking out custom 3D printed parts for my RC drone builds and workshop organizers lately, and threaded inserts are always the weak link—either they spin out or the threads wear down after a few uses. Picked up this Yaocom 300-pack of M3 heat-set inserts on a recommendation from a maker forum, figuring it'd tide me over for a bit, but man, this has become my staple. These bad boys are solid brass through and through, with that aggressive knurling that bites into the plastic like it's nothing. I've melted a ton into PETG and nylon without a single failure; they hold torque like pros even on vibration-heavy drone arms. The 4mm OD and 5mm length are perfect for my typical wall thicknesses—no poking through or weak spots. And 300 pieces? That's enough to outfit a dozen projects without batting an eye, plus they're neatly bagged so nothing gets lost in the junk drawer. Super affordable too, way better than scavenging singles from hardware stores. If you're knee-deep in functional prints and hate re-drilling holes, grab these—they'll save your sanity. Easy five stars from a guy who's broken more tips than I care to admit!

Good amount for the price and work great holding my 3d prints together

They work well. I think out of 40 or 50 inserts only messed up one and it was my fault.

Worked as they should.

I purchased a few packs of these for a good sized project I was working on for a customer. The quality is consistent and the price is great. I haven't had a single insert that is out of spec, and the dimensions all check out. The quantity in the package is great. These install easily with minimal issue provided you size your fastener holes for the proper fit in the material.