Drilling is one of the oldest processes in metal working history and one of the most important in machining. The prime concern is to produce the maximum number of holes at the minimum cost. A twist drill is a rotary end cutting tool that operates under the worst conditions of any metal cutting tool. They are used under the widest spread of conditions and materials, which is why choosing the correct type of twist drill for every job is very important.
The failure of a twist drill is caused by dulling, and dulling is caused by friction. Reduce friction to a minimum and tool life will be highly increased. The best way to reduce friction is by using the proper coolant or lubricant in the drilling process. This method is widely used in machine shops, but it is very inconvenient when using a hand held power tool. All industrial grade Drill Bits are made from highly alloyed steels called HSS (High Speed Steel). The most common HSS alloys for Industrial use are M50, M1, M2, M3, M7, M35 and M42.
HSS 118º Rolled-Forged Drill Bits are manufactured from a high strength molybdenum (M2) tool steel with a 118º point. The conventional 118º point is the most commonly used drill point. It will give satisfactory drilling results in a variety of materials. Each drill is treated with a black oxide wear-resistant finish that insures good lubrication and fast chip removal. (Fractional Sizes: 1/16" to 1/2" by 64ths / Wire Gauge Sizes: #1 to #60 / Letter Sizes: #A to #Z ).
HSS 135º Split Point Drill Bits are manufactured from a high quality molybdenum (M7) tool steel with a 135º split point for fast penetration and accurate starting without using a center punch. Each drill bit is treated with a black oxide wear resistant finish that insures good lubrication and fast chip removal. (Fractional Sizes: 1/16" to 1/2" by 64ths / Wire Gauge Sizes: #1 to #40 / Letter Sizes: #A to #Z).
Cobalt 135º Split Point Drill Bits are made from a premium grade (M42) 8% cobalt steel which is appropriate for drilling in tough materials such as stainless steel, titanium, and other heat-treated steels. These drills can withstand heat and abrasion without affecting their performance. The 135º Split Point gives them fast penetration and accurate starting without using a center punch. Each drill has a straw gold appearance for identification purposes. (Fractional Sizes: 1/16" to 1/2" by 64ths).
Titanium Coated 135º Split Point Drill Bits are manufactured from high quality molybdenum (M7) tool steel with an external coating of Titanium Nitride that makes the surfaces of the drill extremely hard. These drill bits have all the advantages of the 135º split point plus the advantages of the TIN coating, which are: Increase cutting speeds, increase tool life up to 500%, better hole finish, and closer tolerance holes. TIN coated drill bits have a distinctive solid gold appearance. (Fractional Sizes: 1/16" to 1/2" by 64ths).