Raw water pump screws

[Boatyarddog]

Originally Posted by sailingharry

Actually, I'm about 95% sure they are screws. Most water pump covers are held on with fasteners that are fully threaded with Philips heads, and those are "machine screws."

I have seen some people differentiate between a machine screw and a machine bolt, or a machine bolt has a hex head.

If the water pump fastener has a shank, and unthreaded part between the head and the threads, then it would indeed be a bolt.

Google "machine screw" and see if that looks like what holds your water pump cover on. Then see if you can find a Phillips head bolt.

And to the OP's question, on my last boat I replaced the fasteners with SS Allen head, it was an almost impossible place to reach and the Allen head seemed to provide a more positive engagement when removing them. I haven't made the change on my current boat yet, as it is easier to reach.

Pretty sure there is no such thing as a Phillips head bolt. Probably meant as a joke.
https://www.google.com/search?client...1wQ1QJ6BAgMECA
And should use a locking washer, to keep it from backing out, size appropriately.
Boatyarddog

[nigel1]

Maybe something like this, UK stock
https://www.bottomlinemarine.com/pro...m30_8167.shtml

[ozdigennaro]

Standard machine screw probably. DO NOT get slot-head.

[CarinaPDX]

I tracked down hex head machine screws for my Volvo-Penta. I even found the type that have a slot in the hex head. I can use a 1/4" socket wrench to quickly remove them, or combination wrench. The stock round head slotted screws are a first class PITA - get rid of them. Buy either bronze or stainless.

Greg

[thunderhoof]

I replaced the pump cover screws with SS Allen head screws. They were M3 so a metric wrench is required. I put a dab of anti-seize paste on each one. The supplied screws appeared to be brass Phillips head and several shattered the first time I tried to replace the impeller. I had to put the pump on a bench to remove the bolt remnants without damaging the threads in the pump body.

[adjo]

Originally Posted by stormalong

Those screws are bronze. Be careful what you use. Brass or stainless should be OK. Nothing else or you will have serious problems the next time you take it apart.

Do NOT use brass "or you will have serious problems the next time you take it apart".

[goboatingnow]

The thing you’re looking for is a “ knurled “ bolt in the correct size ( m4 I think ) easily got in SS

As with all SS fittings in dissimilar metals , a bit of ceramic anti seize or “ duralac “ zinc chromate helps seizing

[Outdoortony]

Nice I have the screws now but will check these out thanks

[Outdoortony]

Thanks Greg!