Help needed. 7 * 20 * 1 Bolts

G

ghwallice

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Location
Ipswich
I'm currently fitting new cush rubbers to 8 of Zane clutch baskets. The old pressed rivets have come out, leaving a 6.17mm hole in the lugs.

Us Aussies must be stupid. I can buy a 7*1mm tap, but I can't buy 7*1mm bolts. Go figure. We can only count 2 fingers at a time. 6, 8, 10, 12. (Is this because we are so good that we have spent too long giving the rest of the world the forks?) Much unlike you lads in Europe and Japan that can count rationally. 6,7,8,9,10,11,12.....

What I am looking for is about 100 bolts, 7*20*1, grade about 8.8 (maybe less), with a total head depth of, ideally, 3mm. And "safety serrated washers" to suit. If I have to skim the heads I will. I've only got 4.63mm clearance behind the clutch basket

I was given a sample by our local guru, which are too thick in the bolt head area, but if needs be, I can skim the heads of in the lathe.

If someone has a source and can buy for me, I'll send $.

Regards, Greg
 
 
Timesert the holes back to M6.  You could then go socket low head or button head.  3mm is very low though.  On my race bike I timeserted and made a retainer plate a bit thicker and used M6 countersunks and loctite 243.

or

Supercrap Auto used to have 10 packs of M7 hex head bolts, quite long, maybe 40mm.  Some modification would make them work.

or

Bicycles are apparently covered in M7's, don the lycra and head down to your local hipster hangout.  (bigthumb)
 
Greg,

I can source M7x20, 8.8, for you if you like.  No problem at all here.  Standard hex head height is 4.8mm for M7 DIN fasteners, so these will require a bit of re-working. 

I'd recommend using Schnoor type washers, very thin while affording good locking capabilities.

Drop me a PM if interested.

piet
 
SCRMAN - Simmos were great. Out of stock, but found me 7*1*25. Great blokes! Unfortunately-----

Stephen. You turned it all on it's head from my perspective...."Timesert the holes back to M6.  You could then go socket low head or button head.  3mm is very low though.  On my race bike I timeserted and made a retainer plate a bit thicker and used M6 countersunks and loctite 243."

Original holes after rivets removed 6.17mm. Tapping out to 7mm means 7.03 mm, but it would not be a full thread depth in alloy for a 7*1 tap. Concern. 6mm insert 7.30mm. Using meat I don't want to use, but found 6*16 (8.8) button heads (head depth 3.2mm) with a serated schnoor washer (.92mm thick) 6*1*2d helicoils gives me best fit with least possible intrusion to structural rigidity. total height about 4.3mm. Available clearance 4.63 at the back of the housing. Should work well. (plus, of course, Loctite)

Sooo. Thanks to all who have helped! Seems like I was wasting your time. My Lopogies.

Stephen. thanks for fckng up my head more than it is already is, but redirection appreciated.

Regards, Greg
 
Greg

Dumb question have your tired Red ??  inlet manifold bolts on triples are M7.
You could try your friendly Citroen breaker/dealer as common on French cars... or Pug or Renault for that matter.

Or just to f.... with your head this early in the morning what about tossing the M7 tap and going old school and doing it to 1/4 inch
1/4 x 3/4 should do it nicely and would thing even your local Bunnings would sort you.

Now I'll go back to refitting the RAM dash we took out twice to fix a damn HVAC issue...  (blob!) (bolt)
 
Brett said:
Greg
Dumb question have your tired Red ??  inlet manifold bolts on triples are M7.
Click to expand...

yes, Greg makes me very tired  :D

issue with supplying him with the M7 bolts was the quantity he wanted, I don't have an unlimited stock of M7 bolts and nuts
ones he is using at the moment on one clutch were supplied by us but I balked at supplying enough bolts for 7 x Zanes

 
redax5 said:
yes, Greg makes me very tired  :D

issue with supplying him with the M7 bolts was the quantity he wanted, I don't have an unlimited stock of M7 bolts and nuts
ones he is using at the moment on one clutch were supplied by us but I balked at supplying enough bolts for 7 x Zanes
Click to expand...
Seems Greg has a bike courier biz running on a fleet of Zane Laverdas. :D
 
Brett said:
Or just to f.... with your head this early in the morning what about tossing the M7 tap and going old school and doing it to 1/4 inch
1/4 x 3/4 should do it nicely and would thing even your local Bunnings would sort you.
Click to expand...

I/4" isn't a big enough thread. Hole is 6.17mm and thread major diameter is 6.35mm, so a 1/4" tap is barely going to leave a mark in the hole!  Normal hole size for tapping to 1/4" is a bit over 5mm.

If going with British threads, you'd need 5/16" which is bigger than M7.
 
Dellortoman said:
I/4" isn't a big enough thread. Hole is 6.17mm and thread major diameter is 6.35mm, so a 1/4" tap is barely going to leave a mark in the hole!  Normal hole size for tapping to 1/4" is a bit over 5mm.
Click to expand...

Nuh. Helicoiling to 6*1*2d. Tapping drill size for helicoil is 6.3. Stay safe mate. Regards, Greg
 
Dellortoman said:
I/4" isn't a big enough thread. Hole is 6.17mm and thread major diameter is 6.35mm, so a 1/4" tap is barely going to leave a mark in the hole!  Normal hole size for tapping to 1/4" is a bit over 5mm.
Click to expand...
Bloody metric too bloody confusing for this little green duck..........Greg heli ??? shh dont tell Red ...they bloody more trouble than they are worth............ cheers
 
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