Used on injection molding for a tight fit. No need to counterbore or drill the boss hole as the insert has a guide pilot. All nuts are made of high quality brass, which has high hardness, deformation, and reliable for long time use. Easy to install: Since the insert has a valve duct, there is no need to counterbore and drill the hole. Can be installed ultrasonically or heat into a tapered bore, or molded during injection. Color: Gold Material: Brass Package Contents: 800 x Nuts Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. thing. The measurement allowed error is +/- 1-3 cm.