Another threading problem; 1144

[QSIMDO]

Cutting 5/8-18 threads on 1144 stress proof, coming out ragged, chunks missing off the crests, etc.
Is that typical of threading 1144?
Never had problems just turning it.
70 rpm, plenty of oil, can't remember pass depth precisely but not too deep.

[rklopp]

Assuming you are single-point threading, I would not expect the problem you describe. Is the tool dull? Is the material annealed instead of cold drawn or drawn and normalized?

[J Tiers]

1144 normally gives very good threads. Maybe it is NOT 1144?

[old mart]

With single pointing using carbide inserts, it should be fine as long as the edges are in good condition. There shouldbe multiple passes each with a smaller depth of cut as the tool has more to cut as it gets deeper. I have only had rough threads when trying to complete the thread too quickly with greater than normal cut depths.

[MrWhoopee]

1144 should produce beautiful threads. Carbide or HSS? Depth of cut? Feeding straight in or at 29.5° with the compound? And most importantly of all, PICTURES!

[tom_d]

Dull tool, tool way off center height, or the material is not what you think it is.

[Illinoyance]

Sometimes increasing the spindle speed helps. If you are plunge feeding try flank feeding instead.

[Mike72]

When this happens I use a razor sharp tool on center making sure it's cutting to one side. I have had steel that just could not be threaded cleanly because of tear out.

[QSIMDO]

I threaded the other end and was less aggressive with my in-feed. ( I remembered .708 / TPI )
Don't know if that's the correct formula but it worked.
Much better.

[DR]

Is it really Stressproof or just plain 1144? There can be quite a difference.