Metric thread, corrosion-resistant, environmentally protected threaded inserts for wood. More usage and installation: Pre-drill a proper hole and screw in using threaded inserts. Fastener connector with hex socket drive, threaded insert nuts for wood furniture assortment. Applications: These furniture screws are suitable for hardwood and solid wood, ideal for furniture assembly. Features of insert nut: These threaded inserts are installed into a pre-drilled hole by screwing them in; the external protrusions grip the wood, preventing rotation or pull-out. Material: Zinc alloy Color: As shown in photo Package Contents: 40 x Hex socket (8mm) 40 x Hex socket (10mm) 30 x Hex socket (M5x10) 15 x Hex socket (M6x10) 20 x Hex socket (M6x15) 20 x Hex socket (M8x20) Package includes only the items listed above; other products are not included. Note: Lighting and display differences may cause slight variations in color between the image and the actual item. Measurement error allowance is +/- 1-3 cm.