[szicree]

Trying to find four 1/4-20 drilled head bolts to attach my airbox. Found 'em for $43 for a ten-pack. Seems a bit spendy!

 

[grover]

a bit?

I'd be trying to make my own out of hardware store bolts at that rate. but then, I'm a tightwad.

 

[N941WR]

Drill your own

Get one of these jigs and you will be able to drill all the bolts you ever need and it will save you money even though it costs $59.75

(Click on picture for details)

 

[Gary Bricker]

Gary Bricker

Are you wanting 1/4 x 20 threads per inch. If so go to Aircraft Spruce and get a AN4H-?A what ever length. That will get you a drilled head. Less that 1$ each.

 

[az_gila]

Not quite....

Are you wanting 1/4 x 20 threads per inch. If so go to Aircraft Spruce and get a AN4H-?A what ever length. That will get you a drilled head. Less that 1$ each.

..an AN4 is a fine thread - which is 1/4 x 28

Most Lycoming engine bolts are coarse thread, which is the 1/4 x 20 Steve asked about....

 

[Gary Bricker]

Gary Bricker

Sorry, My mistake

 

[Geoff]

McMaster-Carr

Trying to find four 1/4-20 drilled head bolts to attach my airbox. Found 'em for $43 for a ten-pack. Seems a bit spendy!

Last year ACS quoted me more than that for a special low-quantity order, although I needed some extra-long ones because I have a spacer between the airbox and the injector.

I bought a drill jig and tried drilling some Grade 5 and Grade 8 bolts from the hardware store, but that didn't work very well for me (probably operator error).

I ended up ordering some 1/4-20 socket head cap screws (with a drilled head) from McMaster-Carr. Much cheaper and plenty strong enough.

 

[G-force]

Trying to find four 1/4-20 drilled head bolts to attach my airbox. Found 'em for $43 for a ten-pack. Seems a bit spendy!

What length? I stock a few sizes in grade 8 or F911 at work, under a buck each if I remember right.

 

[lrfrey]

Grade 5's and Grade 8's can be drilled if you have a drill press vice. Go slow, keep oiled and expect to brake a few drill bits though!

Larry

 

[wilson]

wag aero

AN74A-4. About $1 ea.

 

[Bruce Reynolds]

Van's has them

The part number is BOLT HEX 1/4-20X.5 DH The price is $1.35

 

[trib]

I purchased grade 8 socket head cap screws from a local fastener vendor. These are about .40 each. The socket head cap screw is much easier to drill than the hex head bolt.