RUIMI Titanium Cobalt Step Drills Bits Multi Hole Cutter 5pcs TITANIUM | HIGH SPEED STEEL: classic high speed steel with titanium coating for proven capability SPLIT POINT TIP | increases cutting speed with self-centering and prevents walking Spiral Flute DESIGN | clears chips faster and allows particles to escape easily Hex SHANK | fits into power tools chuck securely and eliminates slip INCLUDES 10 STEP SIZES | 1# 1/4-1-3/8'' 2# 3/16-7/8'' 3# 1/4-3/4'' 4# 1/8-1/2'' 5# 3/16-1/2'' Titanium alloy coating reduces friction and they are more durable than uncoated drill bits.HSS(High speed steel) has a longer service life. The tapered design is suitable for drilling larger and deeper holes, or enlarging the aperture in areas where it has been drilled. Condition: New Material: High Speed Steel Applicable thickness of steel plate: 5 mm Gross Weight: 451 g Net Weight: 453 g 1#&#034;1/4 - 1-3/8&#034; 10 Steps (1/4;3/8;1/2;5/8;3/4;7/8;1;1-1/8;1-1/4;1-3/8) 2#&#034;3/16 - 7/8&#034; 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) 3#&#034;1/4 - 3/4&#034; 9 Steps (1/4,5/16,3/8,7/16,1/2,9/16,5/8,11/16,3/4) 4#&#034;1/8 - 1/2&#034; 12 Steps (1/8;5/32;7/32;1/4;9/32;5/16;11/32;3/8;13/32;7/16;15/32;1/2) 5#&#034;3/16 - 1/2&#034; 6 Steps (3/16;1/4;5/16;3/8;7/16;1/2)