Hello All,

Time for school!

Due to all the love and care my M7 has been receiving, a few of the cowling screws are starting to round out a bit. I figured what the heck, go ahead and replace all of them.

Using the Maule supplied USB I found drawing #5275F Rev D and the in the parts table, item 7 as the screws in question. They are listed as AN526-10-8. Cool! I figured, just type that in the search box at Aircraft Spruce and I'd have them parts by Wednesday. Yeah, not so much. Nothing matches up of course.

So regarding the AN526-10-8:
-what do the numbers equate to regarding thread and length
-Stainless or CAD? I think stainless would have a "C" in there somewhere?
The washers are AN960-10L:
-Jeremy schooled me on the "L" being thin washers if I remember right
-the holes in the cowling on the bottom (the single screw) the holes are starting to get bigger so what size would be one size up?

Thanks in advance for the education

Tim

Looks like its probably same as Spruce's AN526-1032R8. Its 10-32 truss headed screw 1/2 inch long. Little longer wouldn't hurt. Think mine might be R12s (3/4"). Airplane doesn't care if stainless or cad.

AN526-1032R8 sounds right to me, too -- I've seen a number of places in the parts catalog where the part number isn't quite right, but close enough to make an educated guess like this. Have a look at the Genuine Aircraft Hardware catalog page to see the part number breakdown: https://gen-aircraft-hardware.com/images/pdf/an526.pdf

BTW, if you aren't familiar with them, G.A.H. (https://gen-aircraft-hardware.com/) has the best information about aircraft hardware I've found - just click on the "techinfo" links to see the relevant catalog page. Excellent information and part number breakdowns. A sound piece of advice I got from one of my AMT instructors was to buy one of their catalogs for the toolbox. I did and I use it all the time.

Just to add info, its good to place the washers the correct way around.
Rounded edge towards cowling and sharp edge towards the screw.
This helps prevent the washer cutting into the cowling material, fiberglass or carbon fibre.

Have totally missed the washer placement thing. I kind of like nylon washers there like on the spinner screws.

Thanks Gents!

Order sent and printed off the Aircraft Hardware quick reference guide to hang on the wall in the hanger.

Appreciate the advice

Tim