Cutting fluid

[BATattack]

What cutting fluids are people using for turning, chambering and threading and how are you applying it for each operation? ie brush on, front flush system etc etc

I use rocol for most drilling and tapping in 316 but it's not cheap and 416 is a different material.

[Rich4]

Sutton Venom leaves a nice finish in 416, squirt from the bottle or dip, Tap Magic was awesome but I haven’t seen it for years, Trefolex is also available in a thick oil instead of a paste, which is nice for threading, I’ve never used Rocol so can’t compare sorry, cheers Rich

[KHGS]

Rocol rules, the liquid for reaming and the paste for threading. Rocol liquid would need to be "cut" to use in a barrel flush system.
Keith H.

[Longranger]

Rocol RTD works really well with a nice finish.

[BATattack]

Sounds like I might be on the right track but it's good to consider all alternatives!

I have heard of some using soluble cutting fluid with low or no dilution for front flush reaming.

This guy is making his own and actually looks to do a suprisingly good job! https://youtu.be/wdgGy1lTyQk

[Rich4]

At low rates most cutting fluids will work adequately, machining is always a balance between economy and speed, when you’re more focused on accuracy and maintaining very expensive tooling, cutting fluid cost becomes almost immaterial, personally I wouldn’t risk a reamer to an oil which is slightly cheaper

[williada]

With Keith. Rocol. Thin for flush system. Otherwise short cuts and blow off chips an keep reamer clean, otherwise chamber rings appear.

[Matt P]

I use a flush system with Castrol Ilocut 170, I’ve run out and now using Rigid dark cutting fluid. The Rigid is pretty good but looking forward to the Ilocut becoming available.

[Rich4]

So Rocol RTD liquid? Not cleancut? What do you dilute the Rocol with? Data sheet says compatible with any mineral oil, any preferences?

[KHGS]

So Rocol RTD liquid? Not cleancut? What do you dilute the Rocol with? Data sheet says compatible with any mineral oil, any preferences?

I do not use a flush system so I can't make any recommendations there as I use it "neat" for my purposes. I have "cut" Rocol with WD40 for tapping purposes, some prominent toolmakers recommend auto transmission fluid to "cut" the heavier cutting oils. As an aside transmission fluid is a good quenching oil. I have used drums of Ilocut 170 and 160 cutting oils, I consider them both very good, but I have a preference for Rocol, one downside is that it is much more of a skin irritant than Ilocut.
Keith H.

[pjifl]

On Sulphurized cutting oils - they can leave stains on some metal surfaces which people don't like.

I have used Rocol undiluted for chambers cut in FL sizing dies. Don't really have the volume of work for a flow through flush system. Also another Locally (Qld) made brew made in Bundaberg which was quite good - forget the name. Neither is nice on skin. Yes - I have heard of diluting these with Transmission Fluid for an oil flow system. Transmission oil is non frothing. Old rifle barrels provide the best stainless steel for making dies. Most common commercial stainless steels are not as nice to machine and Rocol is probably the best here.

For what it is worth, on a lot of general work - especially on Al, I use Woolworths spray on Olive Oil a lot. It is ideal for when one uses a Lathe or Mill very intermittedly. Cleaning out used old soluble oil from built in machine tanks is a major job. NO - I am not Green - it just works in many applications well and is easy on skin.

Maybe rather surprisingly I find this also quite adequate when parting Stainless. The spray - while cutting - gets it to the bottom of deep cut off slots very effectively and it works well on stainless barrels for this purpose. Excellent for surface milling on Al. Maybe not for a production environment or heavy threading but for years most of my work was heavy PVC for scientific instruments done dry and metal work was quite intermittent.

Peter Smith.

[BATattack]

At low rates most cutting fluids will work adequately, machining is always a balance between economy and speed, when you’re more focused on accuracy and maintaining very expensive tooling, cutting fluid cost becomes almost immaterial, personally I wouldn’t risk a reamer to an oil which is slightly cheaper

Yep agreed. I do a bit of "agricultural" work and am aiming to do some more precision work so am open to all suggestions on products that are best suited to specific applications.

Matt do you "cut" the Ilocut with anything or just run it neat on the flush system? Does it last or go off? Interesting on the data sheet it says that it's 20% fat. . . . . . Is that what you and Rod do your fish and chips in to shoot so well?

Pete I reckon canola oil might be worth a try from things I need to weld afterwards! Much better than breathing in rocol fumes! Not sure how well it would go on 316 but for aluminium which usually suffers from chips cold welding to the cutting edge it could be a good option.

[Rich4]

316 is a cow no matter which fluid you use in my opinion anyway, 4 series are like butter by comparison, the most important thing I feel is sharp tooling, it’s amazing what can be achieved with slow and sharp, high speed is a great option to have but generally unnecessary without carbide for production, aluminium is better with a thinner fluid, straight thinners is actually decent, also not sure of your background but always check the lathe prior to precision work, twist is more important than end to end, I actually did my trade on mostly agricultural equipment new and repairs, workmanship is more important than what your working on

[BATattack]

Yeah I've done a decent amount of work with 316 and 304 and found rocol was best for that. Slow with a sharp tool and plenty of pressure to keep it cutting. If you aren't getting swarf stop and change something quickly.

[pjifl]

Olive Oil tends not to go gummy with age. I think it is superior to Canola. A spray can lasts and the nozzle never gums up so it is ready anytime.

316 and 304 as mentioned, can be nasty to machine but it seems to depend on the batch - it varies a lot. Once upon a time when Australia produced Stainless Steels, they were superior in quality and more consistent.

A well tested old recipe is Bacon Fat or some equivalent melted and mixed in with a any lighter oil. It can go Rancid however. Put on with a stiff brush.

Peter Smith.