WARNING: Cancer and Reproductive Harm - www.P65Warnings.ca.gov.
Fast service on a quality part
They are screws, they are stainless and the are flathead, so I gave three stars. But if you want to use them on an aircraft for fairings... then get the structural screws with 100 degree angle. These are 82 degrees and do not match your countersink. They do not sit flush, and the rounded instead of sharp shoulders make them look even worse. Not worth the savings.
Please note, Aircraft Spruce's personnel are not certified aircraft mechanics and can only provide general support and ideas, which should not be relied upon or implemented in lieu of consulting an A&P or other qualified technician. Aircraft Spruce assumes no responsibility or liability for any issue or problem which may arise from any repair, modification or other work done from this knowledge base. Any product eligibility information provided here is based on general application guides and we recommend always referring to your specific aircraft parts manual, the parts manufacturer or consulting with a qualified mechanic.
The diameter of the thread on the 4-40 is approx 3/32 and the diameter of the 6-32 is approx 1/8.
We do not stock these with a black oxide coating.
MS51959 units are stainless steel, but do have some magnetism.
The only 2-56 nuts we sell are part number MS35649-224, they are not self locking.