The T50 Genuine Arrow New staples are from quality steel material ensuring your stapling is precise strong and long-lasting. The first time every time. Available in 6mm (1/4 inch) 8mm (5/16 inch) 10mm (3/8 inch) 12mm (1/2 inch) 13mm (17/32 inch) and 14mm (9/16 inch) sizes with a flat crown width of 10mm. Also in stainless steel and monel materials.