aluminum or thin chromoly?

[garredondojr]

I've been reading alot on the forum and trying understand things. i've been reading that aluminum isn't as desirable as I though. most of my reading is stating you need to hard coat anodize it to get it to live? I wanted to build a lite 9mm can and was planning on making it all out of 7075-t6 (modified K 1"-1.125"x6") now i'm thinking a really thin 4140 or 4130 tube would offer more internal volume without sacrificing to much strength or weight. is my thinking wrong? on the same token do you guys think modified k's out of 4140 or 4130 would survive at .030" thickness. how much difference in weight would .030 chromoly be be compared to .055-.0625" 7075?

I do have a friend who would allow me to parkerize my parts if I went with chromoly

Or am I overthinking this? if 7075-t6 will survive without special treatments (anodizing is out but I planned to cerekote the outer tube) I would rather go that route. I plan to use this on a glock 17 and for 22lr. I will also design it to allow a booster in the likely case it's needed.

[cdrissel]

Your tube needs to be thick enough to thread and still be strong.

[garredondojr]

Your tube needs to be thick enough to thread and still be strong.

I can leave the OD larger where threaded like the surefire ryder. I haven't measured it but my plans are to bring the OD to the same height as my sights on my glock (aftermarket but not suppressor height) but will step down after the threads to maintain as thin of a can as possible.

How bad is the errosion on a all aluminum can without any treatment?

[yondering]

When you say erosion, are you concerned about baffle erosion from firing, or corrosion of the tube?

[garredondojr]

When you say erosion, are you concerned about baffle erosion from firing, or corrosion of the tube?

both I assume? guess what i'm after is will a 7075 suppressor give me a decent service life on 9mm and 22lr? talking maybe 30-100 rounds a month 9mm and about half that in 22lr. at least a decade of service life would be nice.

I was looking on evil bay and found that titanium isn't as bad as I assumed. I can get a 28mm diameter grade 5 (6al-4v) bar stock 20" long for $70 shipped

I've never machined Ti before. is there a steep learning curve? how abusive is it on HSS tooling? also I currently only use the brush oiling method will this be enough or do I have to step up to a coolant pump system? I don't mind spending the time behind the machine if I get a better finished product. but if it's going to trash my tooling and require an expensive coolant system i'll stick to other materials.

[CMV]

Yes you will need flood coolant for Ti. You can make an inexpensive cooling system for under $50. Not elegant but will work. If you search my threads, you will find instructions on how I made mine.

Ask Enfield577 about service life of 9mm AL baffles - he makes a lot & can probably give you a good estimated round count before noticeable degradation.

You'll need to be good at grinding & sharpening your HSS tool bits for Ti. You'll need to have a drill doctor or else be good enough on a bench grinder to sharpen your drills too. It will require very sharp tooling & frequent checking/resharpening.

I doubt you'll find 7075 seamless tubing. I'm sure it exists, but I've never come across it sold by the foot. So you're looking at 6061 or 2024 most likely. Of those, 2024 is stronger but it is still AL.

Chrome moly is fine to use - just heavier & you need to do more maintenance to prevent corrosion. But it machines nice & is very strong. If you want chrome moly tube, check out stock car steel - great prices on it & I've been happy with everything I've bought from them & their fast shipping. Also a good source for AL stock & CRS, but I don't think they have 2024 tube.

[yondering]

I turn Ti dry, no coolant. Most of that is done with carbide tooling, with some HSS used for special shapes.

[yondering]

.

I doubt you'll find 7075 seamless tubing.

D cell Maglites. They are way thicker/stronger than needed for 9mm though, so you can remove about half the material from inside or outside.

[mcrump]

Yes you will need flood coolant for Ti. You can make an inexpensive cooling system for under $50. Not elegant but will work. If you search my threads, you will find instructions on how I made mine.

I tried to do a search for your post on making a flood coolant system but using CMV as a search string doesn't work. Too few letters or some such nonsense. Could you either re-post or post the link? I need to make one myself. Thanks!

[propeine]

Yes you will need flood coolant for Ti. You can make an inexpensive cooling system for under $50. Not elegant but will work. If you search my threads, you will find instructions on how I made mine.

Ask Enfield577 about service life of 9mm AL baffles - he makes a lot & can probably give you a good estimated round count before noticeable degradation.

You'll need to be good at grinding & sharpening your HSS tool bits for Ti. You'll need to have a drill doctor or else be good enough on a bench grinder to sharpen your drills too. It will require very sharp tooling & frequent checking/resharpening.

I doubt you'll find 7075 seamless tubing. I'm sure it exists, but I've never come across it sold by the foot. So you're looking at 6061 or 2024 most likely. Of those, 2024 is stronger but it is still AL.

Chrome moly is fine to use - just heavier & you need to do more maintenance to prevent corrosion. But it machines nice & is very strong. If you want chrome moly tube, check out stock car steel - great prices on it & I've been happy with everything I've bought from them & their fast shipping. Also a good source for AL stock & CRS, but I don't think they have 2024 tube.

I've never used coolant with Ti for general turning and have 3 suppressors under my belt that are all or mostly gr5 and gr 9 so I would disagree. Only time I used any cutting fluid was while using a cutoff tool.

[garredondojr]

Yes you will need flood coolant for Ti. You can make an inexpensive cooling system for under $50. Not elegant but will work. If you search my threads, you will find instructions on how I made mine.

Ask Enfield577 about service life of 9mm AL baffles - he makes a lot & can probably give you a good estimated round count before noticeable degradation.

You'll need to be good at grinding & sharpening your HSS tool bits for Ti. You'll need to have a drill doctor or else be good enough on a bench grinder to sharpen your drills too. It will require very sharp tooling & frequent checking/resharpening.

I doubt you'll find 7075 seamless tubing. I'm sure it exists, but I've never come across it sold by the foot. So you're looking at 6061 or 2024 most likely. Of those, 2024 is stronger but it is still AL.

Chrome moly is fine to use - just heavier & you need to do more maintenance to prevent corrosion. But it machines nice & is very strong. If you want chrome moly tube, check out stock car steel - great prices on it & I've been happy with everything I've bought from them & their fast shipping. Also a good source for AL stock & CRS, but I don't think they have 2024 tube.

I've never used coolant with Ti for general turning and have 3 suppressors under my belt that are all or mostly gr5 and gr 9 so I would disagree. Only time I used any cutting fluid was while using a cutoff tool.

Tell me more please.....what grade of inserts/tooling did you use? from the little reading I did it looks like Ti likes to be cut at low rpm/sfm with a fast feed and heavy cut? the part I didn't understand was they said you don't want to overheat Ti but then they say fast and heavy generates less heat than light and slow?? am I missing something because that sounds backwards to my thinking?

[CMV]

Yes you will need flood coolant for Ti. You can make an inexpensive cooling system for under $50. Not elegant but will work. If you search my threads, you will find instructions on how I made mine.

I tried to do a search for your post on making a flood coolant system but using CMV as a search string doesn't work. Too few letters or some such nonsense. Could you either re-post or post the link? I need to make one myself. Thanks!

viewtopic.php?f=10&t=133166


Ti is so expensive and tooling isn't free either. I wouldn't try to drill it to any kind of depth, part it, or do much other than mill a scoop on a K dry. But that's me. Scrap a few inches of material and a decent drill & you're out more than a cheapie DIY coolant setup would have cost...

[propeine]

Yes you will need flood coolant for Ti. You can make an inexpensive cooling system for under $50. Not elegant but will work. If you search my threads, you will find instructions on how I made mine.

Ask Enfield577 about service life of 9mm AL baffles - he makes a lot & can probably give you a good estimated round count before noticeable degradation.

You'll need to be good at grinding & sharpening your HSS tool bits for Ti. You'll need to have a drill doctor or else be good enough on a bench grinder to sharpen your drills too. It will require very sharp tooling & frequent checking/resharpening.

I doubt you'll find 7075 seamless tubing. I'm sure it exists, but I've never come across it sold by the foot. So you're looking at 6061 or 2024 most likely. Of those, 2024 is stronger but it is still AL.

Chrome moly is fine to use - just heavier & you need to do more maintenance to prevent corrosion. But it machines nice & is very strong. If you want chrome moly tube, check out stock car steel - great prices on it & I've been happy with everything I've bought from them & their fast shipping. Also a good source for AL stock & CRS, but I don't think they have 2024 tube.

I've never used coolant with Ti for general turning and have 3 suppressors under my belt that are all or mostly gr5 and gr 9 so I would disagree. Only time I used any cutting fluid was while using a cutoff tool.

Tell me more please.....what grade of inserts/tooling did you use? from the little reading I did it looks like Ti likes to be cut at low rpm/sfm with a fast feed and heavy cut? the part I didn't understand was they said you don't want to overheat Ti but then they say fast and heavy generates less heat than light and slow?? am I missing something because that sounds backwards to my thinking?

Heavy cuts seem to remove more heat with the chips and leave less in the material. Fast and light with any deflection is all of the sudden mostly rubbing instead of cutting and you will ruin a tool quick. I got away with sharp HSS for most work and for all threading. Inside cuts I wound up using an import brazed carbide. Threading I did in back gear at 80 rpm. Everything else on my 22lr and my 9mm can I did in the lowest speed in regular gear. I think it's 300ish. My 1.5in 308 can I did lighten the exterior of the tube in back gear as I was having some issues with rubbing. Since 90 percent of suppressor work is done on the compound I can't really tell you IPR but I can tell you for roughing it was .030 per side DOC and as aggressive as I could feed it. Finishing would be half of that and going for surface finish.

All that said, I'm not a machinist I'm a hack but I'm pretty confident turning Ti now. More so than any other material. Keep your tools sharp and you'll be fine. Also I've drilled 20+ baffles, 3 brakes and 6 end caps all with the same .25in cobalt drill. I think it was 13 dollars at lowes.

[yondering]

I've found the TT style inserts with the smallest tip radius work well in Ti. The negative rake stuff is considerably less effective.

I run relatively slow with HSS in Ti, but turn about the same speeds as carbon steel with TT inserts.

Ti generally isn't difficult to cut, it just gets hot easily, so take that into account. For most turning, it's the insert that takes the most heat, hence my use of carbide instead of HSS inserts.