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Cleaning taps?

Keith Foor

Active Member
Active Member
I have a ton of taps that I got from the son of a retired machinist. Honestly it looks like the guy never used the same tap twice and just kept tossing them into a bucket.
Got taps from itty bitty 4-40 stuff all the way to 1.5 inch.
Some are standard some are custom Like a 1 5/32 24 pitch one that is still in the plastic coating.
Some however are surface rusted a bit and I would like to clean them up in bulk rather than one by one.
Any ideas for bulk cleaning a bunch of taps and end mills. I got a ton of them too.


Active User
H-M Supporter-Premium
I use Evaporust.
I buy it by the gallon and reuse it several times.
I've bought it from several different places.
Harbor Freight, Home Depot and Menard's to name a few.

Bob Korves

H-M Supporter - Premium Content
H-M Supporter-Premium
Brush loose stuff off with a stainless steel toothbrush, wash any oil or grease off with solvent, blow dry with air, soak in Evapo-Rust until the rust is gone, rinse, brush anything remaining with a nylon hand brush, rinse with hot water, blast with air to remove water, (return any that might still have rust to the Evapo-Rust), let stand until fully dry, coat with ATF using an old toothbrush to get into all the nooks and crannies. Yes, I have done several batches of over 100 each, from 2-56 up to 1-1/2" using this technique, and they come out looking and working great! Dies, too...

Edit: Same treatment for end mills.


Active User
Active Member
I would just put the taps in an oil soaked cloth bag to help stop the continuation of more rust. Then, when you need a tap, just grab the one you need and use it. The rust will come off the places where it is used. That’s all you need to worry about. If you are still concerned, then you can fine wire wheel the shank if you want to…Dave.


Active User
H-M Supporter-Premium
Make sure the taps are still sharp after cleaning. Once rust attacks the cutting edges, they are pretty much done.
Just like an old rusted file. Even old oil turns acidic after some time. The best taps are ground and will hold a sharp edge but corrosion will
destroy them fast. Look at the taps under a magnifier to check. A tap is only good if it's sharp.


Global Moderator
Staff member
H-M Supporter-Premium
On my larger taps, I wrap the threaded portion with HF electrical tape for long term storage. Doing this keeps the cutting edges sharp. (Don't know if this is good or bad, works for me) My smaller taps, well, most of them are either kept in the container when bought new or I store them in a multi drawer cabinet. Not the best storage, but keeps them organized. They all get sprayed down with either Starrett M-1 or equivalent, or coated with a R & O hydraulic oil. I know this doesn't answer the question originally asked, but close. Ken