100/50pcs M3 M3*5.7-OD4.6 Thread Knurled Brass Threaded Heat Set Heat Resistant Insert Embedment Nut for 3-d PrinterFeatures- Color: Golden.- Material: Copper.- Size: 0.57 x 0.46 x 0.46 cm.- Used on injection moulding for tightly fixing.- No need to counterbore or countersink the boss hole because the insert has guide pilot.- All nuts are product of effective brass, which has high hardness, no deformation, sturdy and reliable for lengthy use.- Easy to install: From the moment that the insert has a valve conduit, there's no should back-drill and counter-sink the hole.- Can be put in by way of ultrasonic or warmth in tapered bore wire, or molded in throughout injection.Packing list50/100 x embedment nut