This frame is pre-punched with 21/64 inch holes which are intended for 5/16 inch hardware. Equivalent metric hardware is listed below:
1 Bolt: 5/16 inch x 2.5 inch ~ M8x60
2 Bolt: 5/16 inch x 4 inch ~ M8x100
3 Bolt: 5/16 inch x 5.5 inch ~ M8x140
Original archived page — revision 9603, 2022-05-30T15:14:54+00:00, by Tim.