This is a set of step drills made of high speed steel 4241. Different specifications can meet different drilling requirements. The aluminum box can accommodate and protects the drill bits.

Specifications:
Material: high speed steel 4241
Quantity: 5pcs
Size:
1/4" to 1-3/8" (10 steps): 1/4", 3/8" 1/2", 5/8", 3/4", 7/8", 1", 1-1/8", 1-1/4", 1-3/8"
3/16" to 7/8" (12 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8"
1/4" to 3/4" (9 steps): 1/4", 5/16", 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4"
1/8" to 1/2" (13 steps): 1/8", 5/32", 3/16", 7/32", 1/4", 9/32", 5/16", 11/32", 3/8", 13/32", 7/16", 15/32", 1/2"
3/16" to 1/2" (6 steps): 3/16", 1/4", 5/16", 3/8", 7/16", 1/2"
Shank diameter:
1/4" to 1-3/8": 8mm / 0.3in
3/16" to 7/8": 8mm / 0.3in
1/4" to 3/4": 8mm / 0.3in
1/8" to 1/2": 6mm / 0.2in
3/16" to 1/2": 6mm / 0.2in
Package size: 152 * 107 * 43mm / 6.0 * 4.2 * 1.7in
Package weight: 502g / 1.1lb

Packing List:
5 * Step Drill
1 * Aluminum Box