Although it looks simple, there’s a lot of adverse situations that might happen while using hand taps to make threads on holes. Follow this tips to get excellent threads every time.
Know your drill bit
Store your taps with their respective drill bits. If the hole is too big then you’ll have shallow threads and they can get damaged quicker. It can also make your fastener become loose. Smaller holes will damage your tap by forcing it to remove much more material than normal.
Use sharpened taps
Only taps that have good edges can ensure an excellent performance. Use only High Speed Steel taps (HSS) from trusted manufacturers. Keep new taps for your frequently used sizes. Replace worn taps quickly. The worn-edge taps take too much time to create a thread. This type of work will sometimes brake our tools and leave debris on our hole.
Start your tapping straight
To produce an accurate thread it is necessary to ensure that the tap enters the hole at a perfectly straight angle. By starting straight you will reduce:
- Friction
- Wear
- The possibility rupture
The same hole will force the tap to line up. You can chamfer your hole to help guide the tap.
Keep it clean
Take the tap in and out to break the chips, to keep the hole free of burrs. As soon as resistance is felt, return the tap to the outside. In coarse materials it’s very important to keep the tap free of waste. For steel, remove the tap in revers 1 or 2 times to avoid chips being embedded in the bottom of the thread. In softer materials like aluminum, the long chip created needs to be cleaned during the process of the thread. It is likely that for each turn, you’d have to turn back half a turn to break the chip so it won’t be too long and evacuate through the flutes. The smaller the tap, the more frequently you’ll have to break the chip. If you don’t do this, you may saturate your tap and it might get stuck in the hole.
Lubrication
Although the manual threading process does not produce much heat, it is still necessary to lubricate. You will find great benefits in your application using a thread lubricant, soluble oil or even common oils for your machines. This lubrication will help prevent your tap from getting stuck and will allow the chips to be evacuated through the flutes.