135 degree split point Cobalt drills - Easier drilling stainless steel
TTP Hard Drills for stainless steel
TTP HARD DRILLS are designed to drill through the toughest and hardest of abrasive materials such as stainless steel. They are ideal drill bits for drilling stainless steel including most common types of the austentic stainless steel types 200 - 300 can be easily drilled with the correct drill and technique even using a hand drill.
TTP Hard Drills - Drill Stainless Steel
This video shows the TTP Hard Drill drilling into a martensitic grade of stainless steel - showing TTP COBALT Hard Drills drilling through STAINLESS STEEL 17-4 PH (also known a stainless steel 630) a martensitic precipitation hardening stainless steel, versatile with an outstanding combination of properties.
CHOOSING the best drill bit for drilling stainless steel combined with technique and a coolant enables success.
Most common mistakes that people make - Wrong Choice of Drill type
TOO HIGH DRILL SPEED
TOO MUCH PRESSURE
= TOO MUCH HEAT GENERATED - makes the steel EVEN harder to drill !
The work hardening effect when drilling the (austeniti) stainless steel is the main cause of problems. The steel hardens progressively as it is cold worked, it is important to make sure that the steel when deep or small diameter holes are being drilled a cooling oil or paste is used.
A rigid drilling machine ' jig is always the prefered method as it keeps the work piece rigid and drill too. However hand drills can be used.
Using a three-cornered pyramid tip punch is better choice of punch to use when hand drilling - Centre punching with conventional conical shaped punches can result in enough localized work hardening to make drill entry difficult. This can make the drill tip deflect or wander, glaze the surface and/or blunt the drill tip and result in drill breakages, particularly where small diameter holes are being drilled.
Always maintain the feed to cut through the work hardened layer generated as the metal is cut. Dwell or rubbing needs to be avoided. Entry and re-entry after backing out should be done at full speed and feed rate. The operator might have to reduce tool speed to ensure that the feed rate can be maintained, without causing other problems.
During drilling chips must be allowed to escape from the hole being drilled a build up of chips in the hole can cause roughness to the drill wall,more heat, and even drill breakage. TTP Cobalt Hard Drills with a 135 degree point assists with clearing the chips but when drilling deep holes frequently back the drill out but with minimumn dwell
Start slow to find the 'chip' keep the drill cutting and not rubbing
Keep it cool !!!!!! APPLY a cooling aid FREQUENTLY - TTP CUT IT is a ideal suitable coolant to use esp when hand drilling as its easy to apply even at angles - the cutting / cooling paste stays.
The work hardening effect when drilling stainless steel (the chromium in the stainless steel makes the stainless steel harder to drill than carbon steel) is the main cause of problems. Centre punching with conventional conical shaped punches can result in enough localized work hardening to make drill entry difficult. This can make the drill tip deflect or wander, glaze the surface and / or blunt the drill tip and result in drill breakages, particularly where small diameter holes are being drilled. During drilling it is essential to maintain the feed to cut through the work hardened layer generated as the metal is cut.
Drill slowly and allow the bit to do the work. If you apply too much pressure friction will cause your drill bit to redden with heat which in turn will blacken the stainless steel. The same will happen if you engage the drill to its full speed. The trick here is to find a happy medium, that "sweet spot" at which the drill, the bit and the metal cooperate fully.
TTP Hard Drill bits are the best cobalt drill bits for stainless steel, chrome, hardened steel and harder alloys. The TTP Hard Drills 135° split point (self centering) combined with the deeper parabolic flute form (manufactured from Tungsten and Molybdenum for increased Hardness and with Cobalt added to ensure superior heat resistance) ensure that these drill bits are Guaranteed to perform in the most demanding of applications like drilling stainless steel.