Homemade tap

[Mikey]

I started to put my mirror back on my 77 and i seemed to have started to cross thread the hole in the master cylinder
I have a bolt that's the same size and thread pitch
But id rather not have to buy a tap for just 1time
Could i just put a small chamfer on the end of the bolt use the nut when taking it off the bolt to clean up the threads
And use that as a tap

 

[Jim]

Could i just put a small chamfer on the end of the bolt use the nut when taking it off the bolt to clean up the threads
And use that as a tap

Mikey, I've made taps from a bolt before. Taper the end like you said, but also take a skinny cutoff wheel and cut flutes in it so it resembles a tap. For emergency use it'll work pretty good.

 

[46th Georgia]

Mikey, I've made taps from a bolt before. Taper the end like you said, but also take a skinny cutoff wheel and cut flutes in it so it resembles a tap. For emergency use it'll work pretty good.


View attachment 331984

Done that a bunch of times. A guy I worked with in the late 70's taught me that trick.

 

[Jim]

Done that a bunch of times. A guy I worked with in the late 70's taught me that trick.

Learned that from my Dad back in the early 70's

 

[Mikey]

Mikey, I've made taps from a bolt before. Taper the end like you said, but also take a skinny cutoff wheel and cut flutes in it so it resembles a tap. For emergency use it'll work pretty good.


View attachment 331984

Never thought about putting flutes in it
As always guy thanks!!!
I think that thread is 10mm x 1.25
And not the usual 10mm x 1.5
Little harder to get a tap locally for the 1.25

 

[5twins]

Isn't the left hand mirror a reverse thread?

 

[WideAWAKE]

I started to put my mirror back on my 77 and i seemed to have started to cross thread the hole in the master cylinder
I have a bolt that's the same size and thread pitch
But id rather not have to buy a tap for just 1time
Could i just put a small chamfer on the end of the bolt use the nut when taking it off the bolt to clean up the threads
And use that as a tap

Correct tap at the hardware store is probably under 10bucks.

 

[Jim]

Isn't the left hand mirror a reverse thread?

It's the right one. Mikey said the master cylinder mirror.

 

[Mikey]

Isn't the left hand mirror a reverse threadrr

RH mirror

 

[Mikey]

Correct tap at the hardware store is probably under 10bucks.

I'll go back to the store but I'll think all they'll have is the 1.5 pitch and im pretty sure i need
1.25
Im going back to the local store
I got the mirror to be able to check the pitch

 

[Mikey]

I'll go back to the store but I'll think all they'll have is the 1.5 pitch and im pretty sure i need
1.25
Im going back to the local store
I got the mirror to be able to check the pitch

Support my local store
Without them id of bought what i thought was motorcycle specific fasteners online instead of just buying metric hardware
And i can't find what I need i have Jims backup plan

 

[5twins]

Yes, I meant to say the right hand one. I'm pretty sure it's a reverse thread. At least it is on the later MC brackets, you can tell by the line etched into the mirror nut .....

 

[member43148]

Oh Mikey , it’s time for a pic of both your mirror stalks

 

[Mikey]

Just got back from the hardware store and it's a 10mm x 1.25 RH threads
It's an aftermarket MC

 

[Mikey]

Yes, I meant to say the right hand one. I'm pretty sure it's a reverse thread. At least it is on the later MC brackets, you can tell by the line etched into the mirror nut .....

View attachment 331998

View attachment 331999

are there indicators on all bolts for left hand thread ?

 

[Jim]

are there indicators on all bolts for left hand thread ?

Yes, at least there should be.... about 95% do I'd say.
It's a universal standard, left hand threaded anything will have a ring or groove cut in it. From my SG.

Left side, normal right hand threads....

Right side mirror. Left hand threads...

 

[Mikey]

good to know especially when taking something apart

 

[Mikey]

And success
I didn't have a holder big enough for the tap but with a 5/16 socket a small 1/4" drive ratchet and the jobs done
Tap was $8.79 so I'm happy and maybe ill use the tap again

 

[DogBunny]

Yes, at least there should be.... about 95% do I'd say.
It's a universal standard, left hand threaded anything will have a ring or groove cut in it. From my SG.

I never knew that, thanks.


Aside from Yamaha mirrors, the only thing I have that I can think of that is left-handed is the extended arbor on my motor for my grinder/buffer/ wire wheel. Left hand nut, but it's plain, no grooves.
Just thought of another -- gas fittings are left-handed so you can't accidentally cross them with oxygen lines. Looking at images on Google, many lefty gas fittings are grooved, but not all.

 

[Jim]

Looking at images on Google, many lefty gas fittings are grooved, but not all.

As an industry standard, it was about 99.9% universal...... 'till the fuckin' Chinese started making anything and everything. They decided it weren't that important. I've got dozens of old acetylene gauges, fittings, regulators and torches. All of 'em ancient and predate the Chinese's penchent for makin' cheap shit. Every single one has the left hand thread groove cut in 'em.
If you have a nut, bolt, fitting or widget of any kind that's left hand thread and doesn't have the groove... I'll lay ya odds it's Chinese.