WTB: Machinist Help Needed! Custom Fasteners Please!

Well I royally boned myself by tapping the end of my exhaust pipe with a 9 x 1 tap. WTF uses 9 x1? Why do I have a tap for it? "Christ bloody night gown?!"

I am requesting some 9 x1 allen head bolts, BUT I do want to add some tuning ability with them by having different sized holes through the middle of them. I'll buy whatever you make, I would obviously prefer stainless steel, and the head doesn't have to be allen key, I just like things with dude names.

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Giovanni Giarratana /

Why don't you weld the holes shut and re drill and tap them to the size you want instead of making custom bolts, if it's alum it'll be easier trying to find some one to tig it then to do that, if it's steel, weld it your self or have a buddy weld it, idk my 2 sense

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

That sounds fun and all but I don't feel like taking the pipe off to clean it out after drilling. I'm getting lazy with this project as I have spent more time and effort on trying to retrofit this pipe to work for my needs.

Upon further research, only one die came up in a google search, so now I change my request to be less specific!

If any one has 10mm rods with different sized holes, I would be interested in that too, as I could slot it for a flat head driver, and lock nut it as I have this dumb tap.

Thanks for the input Giovanni!!

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Well 9mm is .35" so I guess I could get the .375" OD tubes off McmasterCarr and run them through the die to get em down. .375 is 3/8 for the aluminum page....

Clicky for Steel

Clicky for 6061 Aluminum (1/2 foot sections yay!)

Anyone want some 9x1 hollow threaded exhaust tuning screws?! (edited)

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Just throwing this out there, but machining custom fasteners is a colossal pain in the ass. I've done it before (before you ask, I don't have access to a lathe anymore), and it's really something to avoid if at all possible. Also, you're probably not getting an allen head: the only realistic way to make one is to use a special broach or stamp, and neither are the type of tool most home machinists are going to have in their garage (at least not in the correct size).

You could probably get someone do to it, but it won't be cheap. As in it would probably be cheaper to buy a new exhaust pipe and a less wonky tap and start from scratch.

Or just weld it up or drill it out and use larger bolts. That would almost certainly be your easiest bet.

If you absolutely must have custom fasteners, Fastenal and a bunch of other companies offer custom services. They're not cheap, but they'll get you whatever weird shit you need.

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

^ cool thanks Aaron I think I will have to decide on $ vs. labor. I like the idea of custom fasteners which I now know is feasible with hand tools and rods in 1/2 ft sections from Mcmastercarr.

My bill for three different 3/8" OD with various ID's and a 9 x 1 tap is 52 plus shipping....

After a bit of googling, I found these:

Hollow M6 bolts for BMX stems

I don't know how much flow they will allow, but I work at a bike shop and can probably get some cheap.....

It looks like the estoril uses 8mm bolts with a 2 and 4 mm hole option. I'm considering reaming this sucker out to 10mm, running a 10 x 1 tap (common bicycle derailleur hanger thread) and drilling some holes up in some old bolts I know I got laying around. The engine is an 80cc so I want a bit more option rather than the estoril pipe.

Sorry to anyone who reads all of this thread. I wish I could relocate this to the performance or general thread now. MY BAD (edited)

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

What exactly are you doing? I'm curious now. You have any pictures?

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Rather than all the drilling you could use a brake fitting, but you would of course need a tap with the right thead.

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

^that's a good thought, I didn't think of those cute little guys.

It's gotta work better than this wine cork!!!!

It's a Yamaha riva 80cc scooter. Blasphemous!!

The pipe is a yz80 pipe, and it really unlocked this little puppy. backed off at 60 on the first day I installed it, but the noise was astoundingly loud, hurt through the helmet, and henceforth I need a baffle which fit better as a sidebleed.


Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Found an interesting solution in a google search, I'm not usually a fan of standard fasteners, but in a case like this:


"I've given up hope on finding an M9x1.00. I've called over 20 different specialty fastener places, and even several specialty metric fastener places. This thread is very rarely use, and seemingly only rod cap bolts, and differentials, but haven't been able to get any good dimensional info on them.

I've also got a quote for having a custom bolt supply company at $19.50 each. Yikes.

Used top end for my bike is $275. New cylinder $575, and would need a piston, and all the stuff that goes with.

But, I have decided that I can use a 3/8-24 tap. 24 threads per inch equal a pitch of 1.04 mm, super close to the 1.00 pitch already tapped. The major diameter of the 3/8's tap is .3750 which equals 9.52mm. Recommended bore for 3/8's tap is 3.20, a good hard measurement shows the minor of the tapped hole to be 3.12-3.14. Should be able to tap it right out to the 3/8's." (edited)

Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Hey thanks Macelius!

I would have considered that had I not already drilled out these bicycle derailleur bolts, and considering the hole is already 9 mm I assume this 10 x 1 tap will do fine cutting through the unused 9 x 1 threads.

The bracket is a derailleur hanger I had laying around, and it worked great thankfully!


Re: WTB: Machinist Help Needed! Custom Fasteners Please!

Cool, yeah if you've got the meat to tap out to 10x1 might as well :)

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