Seat Belt Crotch Strap Bolt Size?

I am adding a 5 point seat belt kit into my RV8A. It already came built with the crotch strap bracket. Does anyone know what type of AN bolt is used for these? I imagine it is some sort of drilled shank for a castle nut and cotter pin? Thanks.

no drilled bolts for the straps according the -7/-9 plans…

AN4-5

On my 8 plans, it shows AN4-5 drilled bolt with washer, castle nut and cotter pin on rear shoulder straps, front and rear lap belts. There's no call for both crotch straps.
I used the same bolt/combination for my crotch straps.

riseric said:

On my 8 plans, it shows AN4-5 drilled bolt with washer, castle nut and cotter pin on rear shoulder straps, front and rear lap belts. There's no call for both crotch straps.
I used the same bolt/combination for my crotch straps.

Click to expand...

Thanks, I searched all the drawings and I couldn't find it. I guess they never specified what to use. I'll do the same as you did.

whose belts you installing"

Vans
Simpson
Hooker
etc?

That OEM bracket will determine the hole size. Drill and ream for a #3. It's easy to upsize if the bracket calls for it. Beats making a bushing.

Freemasm said:

whose belts you installing"

Vans
Simpson
Hooker
etc?

That OEM bracket will determine the hole size. Drill and ream for a #3. It's easy to upsize if the bracket calls for it. Beats making a bushing.

Click to expand...

Vans standard 5 point belt

I would suggest getting the belt in hand before installing the brackets. I followed vans plans for the sub belt mounts, but Hooker has recently changed the bushing in thier harnesses. Not only did the bolt size not match, but the spacing between the plates was wrong too. Might be worth holding off until you can confirm all the sizes with parts in hand.

riseric said:

On my 8 plans, it shows AN4-5 drilled bolt with washer, castle nut and cotter pin on rear shoulder straps, front and rear lap belts. There's no call for both crotch straps.
I used the same bolt/combination for my crotch straps.

Click to expand...

I'm glad you included the plans drawing. I'm in the process of fitting my harness anchors now; I riveted the aft shoulder anchor straps to the top aft skin ages ago without giving it a second thought... and there is absolutely not enough clearance to get that bolt in from the top as illustrated. Was that bolt supposed to be in place during riveting? Did I miss something? Should I attempt to increase the bend in the strap without pulling the skin and deforming it? Has anyone else dealt with this? Yesterday I spent over an hour on my back in the aft baggage pit trying to see if I could get the bolts in from the bottom (NOT best practice) and get the washer and nut on enough to align the castle nut slots with the cotter pin hole. So far, no success; thinking of trying again with thin -L washers. But I know this isn't the right way to do this. I'll take any available feedback.

Martin,
I don't remember about my rear shoulder strap bolts direction.
But I suspect they're with the head on top, best practice, but can't confirm until I go the hangar.
Otherwise, it would have bothered me...
I have a vague remembrance of lightly prying the belt anchor downwards to get the bolt in from the top.
And no, instructions don't mention to insert the bolt before riveting the anchor to the top skin...

riseric said:

Martin,
I don't remember about my rear shoulder strap bolts direction.
But I suspect they're with the head on top, best practice, but can't confirm until I go the hangar.
Otherwise, it would have bothered me...
I have a vague remembrance of lightly prying the belt anchor downwards to get the bolt in from the top.
And no, instructions don't mention to insert the bolt before riveting the anchor to the top skin...

Click to expand...

You were right. I was leery of pulling down on the anchor straps because I didn't want to deform the skin at all, but with a little careful persuasion I got the bolts in from the top. Felt pretty silly about wasting two hours trying to get it wrong... but all's well that ends well. Aft belts are finally properly secured... phew. And I apologize to Majorpayne317641 for the thread drift.