1/4 28 UNJF 3A threads. Got an RFQ and need advice.

[DanASM]

316 SS .500" round flat head .050-.100 thick, .800-.850 long. Threads are .750" long.

I have found that gages can be gotten easily but not cheaply. I also see some of them say "pre plated" on them. Does that mean the gages are not plated? Or the gages are for the thread size pre plating?

Also I know threads can get very intense if they need to be. I have never needed to pay too much attention to them over the years.

I noticed it says these threads need a radius root. Can I machine this with regular chasers and just not cut as deep? Or will I get a flat bottom no matter how deep or shallow I cut them?

I dont see much for UNJF 3A chasers or dies.

Or should I send this to a swiss shop? Single point with a propper UNJF 3A insert?

Thanks in advance.

 

[Milland]

How many? If you have the option, contract this to an actual screw manufacturer, you'll get rolled threads which are generally superior to cut threads for screws.

Second choice would be Swiss with the proper J thread inserts. Regular threading inserts will not give you a J root radius.

 

[camscan]

316 SS .500" round flat head .050-.100 thick, .800-.850 long. Threads are .750" long.

I have found that gages can be gotten easily but not cheaply. I also see some of them say "pre plated" on them. Does that mean the gages are not plated? Or the gages are for the thread size pre plating?

Also I know threads can get very intense if they need to be. I have never needed to pay too much attention to them over the years.

I noticed it says these threads need a radius root. Can I machine this with regular chasers and just not cut as deep? Or will I get a flat bottom no matter how deep or shallow I cut them?

I dont see much for UNJF 3A chasers or dies.

Or should I send this to a swiss shop? Single point with a propper UNJF 3A insert?

Thanks in advance.

Pre plated means the gauge is for a pre plated screw.
The root of the thread is minor dia. so depth of cut will not give you a flat bottom.
Speak to your chaser supplier and ask about the radius.I am sure that if you buy the chasers for that particular thread then you will be good to go.

 

[camscan]

316 SS .500" round flat head .050-.100 thick, .800-.850 long. Threads are .750" long.

I have found that gages can be gotten easily but not cheaply. I also see some of them say "pre plated" on them. Does that mean the gages are not plated? Or the gages are for the thread size pre plating?

Also I know threads can get very intense if they need to be. I have never needed to pay too much attention to them over the years.

I noticed it says these threads need a radius root. Can I machine this with regular chasers and just not cut as deep? Or will I get a flat bottom no matter how deep or shallow I cut them?

I dont see much for UNJF 3A chasers or dies.

Or should I send this to a swiss shop? Single point with a propper UNJF 3A insert?

Thanks in advance.

Pre plated means the gauge is for a pre plated screw.
The root of the thread is minor dia. so depth of cut will not give you a flat bottom.
Speak to your chaser supplier and ask about the radius.I am sure that if you buy the chasers for that particular thread then you will be good to go.

 

[DanASM]

QTY 250,500,750

If the threads were something more standard this would be a good part for my machines.

I dont have a chaser supplier. I bought out Greenfield Tap and Die's tool crib 25 years ago. I still have lots of new old stock.

I think we had found a supplier to make customs chasers this past year and it ws like 400 bucks and 30-60 day lead time. I think it was in Toronto Canada too.