ISO 11381:2016 specifies requirements for ISO metric screw threads for use with spectacle frames. Provision is made for screw threads of the following nominal sizes: S0,8 × 0,2; M1,0 × 0,25; M1,2 × 0,25; M1,4 × 0,3; M1,6 × 0,35 and M2,0 × 0,4 and for related taps and gauges.