28mm → 1-1/8" Imperial
The nearest imperial equivalent of 28mm is 1-1/8" (0.58mm difference).
A 28mm socket or wrench is closest to 1-1/8" imperial (28.58mm), a difference of 0.58mm. The gap is significant — using the imperial size risks rounding the fastener. Use the correct metric socket.
The 0.58mm difference may cause the socket to slip or round the fastener head. Use the correct metric size whenever possible.
Related Sizes
About 28mm Conversion
A 28mm metric socket or wrench is closest to 1-1/8" imperial (28.58mm), with a difference of 0.58mm. The gap between sizes is significant — using the imperial substitute risks rounding the fastener head. Always use the correct metric socket. The second-nearest imperial size is 1-1/16" (26.99mm, 1.01mm off). Heavy equipment. When working on mixed metric and imperial fasteners, a combination socket set covers both systems and eliminates guesswork.