Screw for front of top cowl

[r0ckst4r]

This has been harder for me to find than anticipated.  I am looking for the part number for the 4 screws that go on the inside of the engine cooling air intake that fasten the top part of the cowl down.  They are 10-32 thread screws and are not spring loaded like the majority of the other screws.  I took them to the hardware store but they do not have a screw that matches because the head of the screws at the store are not as shallow and they do not fit nice and flush in the dished washer.  I want to order this online but I think I need the exact part number so I don't end up with a screw that's "close" but doesn't fit flush.

[Guest]

AN 509 also available as MS24694 series screws. Available in steel and stainless steel.

Clarence

[carusoam]

1 hour ago, r0ckst4r said:

This has been harder for me to find than anticipated.  I am looking for the part number for the 4 screws that go on the inside of the engine cooling air intake that fasten the top part of the cowl down.  They are 10-32 thread screws and are not spring loaded like the majority of the other screws.  I took them to the hardware store but they do not have a screw that matches because the head of the screws at the store are not as shallow and they do not fit nice and flush in the dished washer.  I want to order this online but I think I need the exact part number so I don't end up with a screw that's "close" but doesn't fit flush.

r0ck,

You really didn’t go to the hardware store to get aviation hardware..?  

Some hardware stores have an aviation aisle, but...

The reason aviation hardware is a different shape... is to keep people from accidentally substituting hardware that looks good for hardware that is good...

Standard screws have a different angle at the head... so they won’t fit flush...

The various pieces of hardware you are describing have names...  from simple to specific... like a quarter turn fastener...

The parts manual for your plane is a great reference to have... it specifically details the fasteners you are replacing with the specific washer that may be required...

Working with a mechanic is a great way to keep from making simple mistakes...

Aircraft Spruce sells aviation hardware... there are a few other resources listed around here for that too..

PP thoughts only, not a mechanic...

Best regards,

-a-

[MIm20c]

After you get new SS screws buy a stubby philips head and shorten the handle another inch or so. That’ll help against scratching the paint and stripping the screws. 

[Ragsf15e]

Order lots of screws from AC Spruce.  Get these, backups, and definitely some for bottom panels.  Anytime one isn’t perfect, replace it. 

[r0ckst4r]

@M20Doc thanks a million.   New screws and back ups are on the way

[Guest]

Just now, r0ckst4r said:

@M20Doc thanks a million.   New screws and back ups are on the way

Be sure to use the dimpled area washer to protect the composite cowl.

Clarence

[r0ckst4r]

2 hours ago, M20Doc said:

Be sure to use the dimpled area washer to protect the composite cowl.

Clarence

Yes the washers are all good and all there.  Thanks again. 

[dogbocks]

Just wanted to add:

"hardware store" countersunk screws are 90° counter sink angle.

All A/C countersunk screws are 100° angle

McMaster has 100° stuff, CAD plated too, and sometime can have much faster shipping than Spruce, depending on where you live.