The specification of hex socket:
Hex Bolt and Nut for NEMA 17: M3*6mm
Hex Bolt and Nut for NEMA 23: M5*25mm
Hex Bolt and Nut for NEMA 34:M6*30mm
The package include 100pcs bolt and nut, you can choose any specification of above. such as 40pcs for nema 17+40pcs for nema 23+20pcs for nema 34.
Attention: Each one stepper motor need 4pcs bolt and nut.
Any combination is available. Just tell us when you make order. or we will send out randomly.