Which Tap is Best for 303 Stainless Steel?

[Agrean]

Hello friends.
First, I apologize for my bad English. I need your experience. I want to produce a piece, but I have a problem with tapping. The material is 303 stainless steel. I need a M2 tapping to this part. Approximately 200-300 pieces of M2 tapping will be made. For 303 stainless steel which tap do you recommend? How many mm drill and speed / feed do you recommend?

 

[berkeman]

Hello friends.
First, I apologize for my bad English. I need your experience. I want to produce a piece, but I have a problem with tapping. The material is 303 stainless steel. I need a M2 tapping to this part. Approximately 200-300 pieces of M2 tapping will be made. For 303 stainless steel which tap do you recommend? How many mm drill and speed / feed do you recommend?

Are your taps wearing out earlier than expected? I do not see the issue with using a standard tap for this application.

 

[Agrean]

Are your taps wearing out earlier than expected? I do not see the issue with using a standard tap for this application.

I haven't tried it yet. So you're saying cheap HSS taps would be enough? Example this?

 

[berkeman]

I don't use cheap taps. Why would you? Especially if you are planning on tapping many holes...

 

[Agrean]

I don't use cheap taps. Why would you? Especially if you are planning on tapping many holes...

Is there a tap you can recommend?
<< Spam links deleted >>

 

[berkeman]

Is there a tap you can recommend?
<< Spam links deleted >>

I have a feeling that this has been a spam setup thread, and I bit the bait. Just buy normal quality taps from your local supply store.

 

[Agrean]

I have a feeling that this has been a spam setup thread, and I bit the bait. Just buy normal quality taps from your local supply store.

I don't spam Sorry for upload pics. I am from Turkey and there is all local supply say don't have M2 tap. If you can give me brand or tap link I would be happy. Thank you.

 

[AZFIREBALL]

 

[Ranger Mike]

I suspect the SS is work hardening.
In my experience of drilling stainless, slow speed and heaps of pressure, together with good lubrication/cooling, are the answer
Always use a slow rpm and a heavy feed rate. If at all possible flatten the point of the drill out more than the standard angle. Every thing that is hard to drill: use a wider point; every thing soft then a sharper point on the drill. Use mucho coolant.DON"T STOP until you the through or at your stopping point. It you stop, it'll harden and getting started again will be difficult.

 

[jrmichler]

What @Ranger Mike said, plus make the tap drill slightly larger. Most tap drills are sized to make a hole that results in (I think) 75% thread depth. I did some tests once with larger tap drills to get 50% thread depth and found no decrease in strength. Those tests were to help out the machine shop with a similar problem - tapping small deep holes in hard to tap material.

 

[Baluncore]

When threading stainless steel you should use “Cobalt High Speed Steel” drills and taps. CoHSS.
It comes in two common grades, M35 and M42.
https://en.wikipedia.org/wiki/High-speed_steel#Cobalt_High_Speed_Steels_(HSS)
CoHSS tools are expensive, but it is often the only way to cut such a small thread. You may be able to buy a spiral tap in CoHSS.
Avoid spiral thread-flow taps that do not cut, they deform malleable materials.

Google 'cobalt M2x0.4 spiral tap' or search ebay