1 (edited by bertinol 2013-08-23 17:34:58)

Topic: Dzus screws for engine cover

Does anybody know where I can source the Dzus quarter-turn screws that are used to hold down the engine cover? I gather that Dzus has been bought by an American company and it cancelled production of the size I need.

As far as I can make out, the head is inscribed with
A 15-90 but the writing is hard to decipher.

(NB: I later discovered it is really AJ5-90)

The shaft is one inch long.
The top section is 9/16 inch long by 1/4 inch diameter.
The bottom section is 7/16 inch long with a diameter of 5/16 inch.
The usual Dzus quarter-turn mechanism is at the bottom.
The head is wide with a slight dome. I'm not fussy about the head.

They were used in a 1975 Contessa 26.

thank you


Re: Dzus screws for engine cover

Re: Dzus screws for engine cover

As reported elsewhere, I bought some Dzus fasteners on eBay and they work just fine, ending an 18-month search!  Make sure you order part no. "Dzus AJ5-90". I tried AJ5-65, but they are a little short.
For people unfamiliar with Dzus fasteners, they really work a treat. You insert them into the hole, give them a quarter-turn with a dime and they lock the cockpit floor down tight.
They were designed to hold down the cowlings on airplanes, racing cars and sport motorcycles where you have to act fast with no chance of breakdown. That means they work well on Contessas!

Re: Dzus screws for engine cover

What grade of stainless steel can you have?

Re: Dzus screws for engine cover

The ones that came with the boat were stainless steel, of good quality and apparently indestructible. They've lasted for 38 years.
The ones I bought recently on eBay were also very good, but not stainless. They look very good and work well. Time will tell.
I have also seen some cheap knock-offs that were much lower quality, poorer quality machining. One broke the first time I used it.
I tried sourcing stainless steel ones from the manufacturer and was told I would have to buy a minimum of 500 at some huge price; the cheap knock-offs were $5 each; the good ones on eBay were $1 each, plus postage of course. 

Not a very technical answer but the bottom line is that you only need a dozen or so. You can't lose at $1 or $5 each.