Neiko 10181A Quick Change HSS Titanium Coated Spiral Grooved Step Drill Bit 3-Piece Set | 31 Step Sizes in One Kit … 3 PC STEP DRILL BIT SET Size:3 PC STEP DRILL BIT SET Here's an example of how

Here's an example of how an interior cut-out might be used as a hand-hold

Acetone can be used instead of isopropyl alcohol

5 REPLACEABLE SILICONE SMOOTHER - The Caulking Tools was designed with Non-slip push-pull button

35mm)3/32''

they are purposely designed to favor and maintain a cool and stable cutting pattern and reduce wear and tear

Neiko 10181A Quick Change HSS Titanium Coated Spiral Grooved Step Drill Bit 3-Piece Set | 31 Step Sizes in One Kit … 3 PC STEP DRILL BIT SET Size:3 PC STEP DRILL BIT SET Here's an example of howNeiko 10181A Quick Change HSS Titanium Coated Spiral Grooved Step Drill Bit 3 Piece Set 31 Step Sizes in One Kit The Neiko Quick Change Titanium Spiral Grooved Step Drill Bit is constructed of HSS and titanium nitride coating. Features 3 step drill bits with the following corresponding sizes: 13 Step Drill (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 inch) 6 Step Drill (3 16, 1 4, 5 16, 3 8, 7 16, 1 2 inch) and 12 Step