• sac02
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Topic: 3-inch washers?

Just making sure I'm reading this correctly.  Rule 3.5.1 states, "...3-inch or larger load washers are required when mounting to sheetmetal."

Our sub belt will probably mount to the unibody, so we need to use a 3" washer on the backside? 

And to be 100% thorough, a 3"x3" peice of plate with a hole in it is OK as a washer, right? b/c I don't think anyone sells 3" washers, at least for 3/8" bolts, at least that I've seen.

  • RobL
  • RobL
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Re: 3-inch washers?

McMaster PN 91525A144

http://www.mcmaster.com

--Rob Leone Schumacher Taxi Service
We won the IOE at Southern Discomfort.
We got screwed at The Real Hoopties of New Jersey  and we took cars down with us.
We got the curse at Capitol Offense but they wouldn't let us destroy the car.

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  • sac02
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Re: 3-inch washers?

Wow, fail on my part for not remembering that McMaster has every peice of hardware ever conceived

  • JThw8
  • JThw8
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Re: 3-inch washers?

sac02 wrote:

Wow, fail on my part for not remembering that McMaster has every peice of hardware ever conceived

I actually found a few pieces they don't sell during my build, but they are close.

http://wartburg.misfittoysracing.com
OTTER: "I think that this situation absolutely requires a really futile and stupid gesture be done on somebody's part."
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  • sac02
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Re: 3-inch washers?

RobL wrote:

McMaster PN 91525A144

http://www.mcmaster.com

" Minimum Thickness  -  .05" "
" Maximum Thickness  -  .08" "

Guess I could stack 2 or 3.
So even McMaster doesn't have washers both large enough OD and thickness.
Even the hardware specifically sold by race supply companies for harness mounting use 2" washers.

Seriously, where did the 3" washer rule come from?  And is EVERYONE having to use a 3.5" hole saw on mild steel sheet to meet this rule?

  • From: Craphole, NJ
  • Registered: 2009-05-01
  • Posts: 517

Re: 3-inch washers?

sac02 wrote:

Just making sure I'm reading this correctly.  Rule 3.5.1 states, "...3-inch or larger load washers are required when mounting to sheetmetal."

Our sub belt will probably mount to the unibody, so we need to use a 3" washer on the backside? 

And to be 100% thorough, a 3"x3" peice of plate with a hole in it is OK as a washer, right? b/c I don't think anyone sells 3" washers, at least for 3/8" bolts, at least that I've seen.

I made a bunch of harness "washers" with 1/8" thk steel plate cut into ~4" squares with a 7/16" hole drilled in the middle for harness eyebolts.

http://www.ducttapemotorsports.com/
http://www.teamdfl.com
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  • Mulry
  • Mulry
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Re: 3-inch washers?

TeamDFL wrote:

I made a bunch of harness "washers" with 1/8" thk steel plate cut into ~4" squares with a 7/16" hole drilled in the middle for harness eyebolts.

Ditto for seat mounting bolt "washers."

Pat Mulry, TARP Racing #67

Mandatory disclaimer: all opinions expressed are mine alone & not those of 24HOL, its mgmt, sponsors, etc.
  • RobL
  • RobL
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Re: 3-inch washers?

Or...
http://www.saferacer.com/g-force-gf100- … ductid=875

We made our own out of 3"x3" steel bar.

--Rob Leone Schumacher Taxi Service
We won the IOE at Southern Discomfort.
We got screwed at The Real Hoopties of New Jersey  and we took cars down with us.
We got the curse at Capitol Offense but they wouldn't let us destroy the car.

RobL's Website