Door-Knob Set Screw...?

[Osprey69]

We have a 1985 Gulfstar 49 with, with I believe, Perko door latches. The needed set screw defies all current reference points. Fine thread, but not matching any metric or imperial sizes that i can identify.

Help!

Thanks in advance

 

[OldDan1943]

Osprey, not knowing the location of "Marion", I suggest the door knob to your local hardware store or marine supply store and start searching there.

 

[RT Firefly]

Greetings,
Mr. O. Re-tap to a known thread size, perhaps?

 

[Comodave]

Maybe take it to a Fastenal.

 

[Osprey69]

Been to three different hardware stores...big and small box. Fits none of the thread guides. Metric or imperial Very obscure...

Thanks for the suggestions.

 

[OldDan1943]

Any chance it is ASA thread?

 

[ranger58sb]

We have a 1985 Gulfstar 49 with, with I believe, Perko door latches. The needed set screw defies all current reference points. Fine thread, but not matching any metric or imperial sizes that i can identify.

Help!

Thanks in advance

McMaster-Carr (mcmaster.com) includes threads-per-inch in their various screw descriptions. That's not an easy thing to count, but might help...

-Chris

 

[Bill V]

Have you thought of contacting Perko directly?

305-621-7525 (Phone)
305-620-9978 (Fax)
sales@perko.com

 

[Osprey69]

Been trying to reach Perko...Will look at McMaster options. Thanks to all.

 

[Bill V]

We have a 1985 Gulfstar 49 with, with I believe, Perko door latches. The needed set screw defies all current reference points. Fine thread, but not matching any metric or imperial sizes that i can identify.

Over the years I have salvaged a few boats and usually save lots of hardware that Perko manufactures, mainly because their products are good quality and because they are expensive. I probably have a dozen of the Mortise latch sets both in locking and non-locking. Post a pic of yours and what screw you are looking for and I can probably supply you one.

 

[Hippocampus]

We had to get additional keys for Perko locks. Same kind of problem. No lock smith had the appropriate blanks. Ended up contacting US importer. They were very helpful. Google it for address. Don’t know current contacts. Have repetitively fooled with those set screws put an indent in which when you want to tighten the knob causes the set screw to go into the old indent. A PIA. Have someone press on the other knob while you press on yours and tighten the set screw. We had levers not knobs so wanted them horizontal when done. It was hard to not end up in the old indent.

https://www.perko.com/where_to_buy/

 

[FF]

I would go to a hardware store that has the huge wall of screws and other items.


IF you can find any screw that fits , it can be cut down and with a hacksaw a slot for a screwdriver blade created.

 

[High Wire]

On your boat is there another similar door knob? A closet or head door that you can borrow the set screw to take to the hardware store.

 

[Marco Flamingo]

I agree with simply tapping the hole to the next size up in something that is readily available. If you absolutely need to get the same diameter and pitch, you may be able to find a woodwind repair person who can fabricate a little odd-ball screw. European instrument manufacturers in the late 1800's often made their screws in house to whatever diameter and pitch they wanted. Those musical instruments are often worth enough to justify having a missing "in house" screw fabricated. Probably not so with your project. A custom screw will likely cost the same as a new handle, lock, and maybe even a new door.

 

[C lectric]

Instrument repairs. Good suggestion. Some watchmakers and clock repair people can do this type of work also

 

[mike66]

Seems strange a big company like Perko uses oddball screws.

 

[Comodave]

If you can’t find it, I would just drill the hole out a bigger size and then tap the new hole to a size that is readily available.

 

[Hippocampus]

We bought a dozen of these set screws directly from the US distributor in order to have spares. Would again suggest contacting them and getting multiple spares. No longer have that boat and left new owner the part supply list for him. But still think a internet search and perhaps a call to local vendor to get distributors contact information is the way to go. The set screw takes a small hex head to tighten it.Better toque than you’ll get with a flat head screwdriver. Use OME part. A drop of blue lock tite done.

 

[Osprey69]

Brought a matching screw to 3 hardware stores. Nothing fit. Brought it to a fine machinist who found it is 5/16 -24. I hope he is right as I just ordered some from McMaster.

If not re-tap is plan B.

Thanks to all for suggestions.

 

[skyhawk]

Seems strange a big company like Perko uses oddball screws.

I was thinking the same.... and that perhaps it was something normal but had been cross threaded or otherwise mangled at some point....

but I hope your machinist was correct!...although I'm surprised that size didn't show up at a good hardware store....

 

[RT Firefly]

Greetings,
Mssrs. O & s. Indeed. 5/16-24 is not only common, it's HUGE for a doorknob. Perhaps run a tap through the threads but be VERY careful. It may NOT be a 5/16-24. I thought of cross threading as well.

 

[Andiamo2018]

Just last week I contacted Perko in Fla and they were great. I emailed pictures of what I have and they sent me the part I needed in addition to giving me the correct part number. I was impressed with their high level of help.

 

[MVDarlin]

Can you drill and through bolt or rivet?

 

[OldDan1943]

Just last week I contacted Perko in Fla and they were great. I emailed pictures of what I have and they sent me the part I needed in addition to giving me the correct part number. I was impressed with their high level of help.

Did they tell you the diameter and thread/inch??
Did you ever tell us what happened to the original screw?

 

[Capt Ray]

We have a 1985 Gulfstar 49 with, with I believe, Perko door latches. The needed set screw defies all current reference points. Fine thread, but not matching any metric or imperial sizes that i can identify.

Help!

Thanks in advance

Had SAME problem.
It was easy to remove the whole mechanism off the doors to a local locksmith on Long Island NY. They fixed it within an hour or so by re-tapping the lever to a thread that was more common, and I left with something that has been working ever since.

Locksmiths were not mentioned in any of the previous threads, and so I figured I would share my solution with you. They seem to have a 'git er done' attitude and got me back and running. Bring a nice cup of JO with you for the wait.

Shellerina.com

 

[ronobrien]

I had that problem recently with a Force10 stove. I took it (the screw) to a local machine shop and in about 15 minutes he told me exactly what I needed. Got the drill and tap from McMaster Carr.

 

[Bill V]

I find it hard to believe that Perko doors use a 5/16¨ 24 set screw. That seems very large and is much bigger then on my Perko door latches. It is also a very common thread size too.

 

[ABfish]

Reminds me of a small plate tamp that we had at work. The piece was made in Germany.

We lost a clutch mounting bolt. Spent a couple of hours trying to find the "correct" metric fine-thread bolt. No luck.

The bolt was a 7/16 inch, NF thread. Go figure.

 

[CmdrDick]

Perko handle screw

I recently got locked out by a worn 35 year old Perko lockset.

The plastic internal cam wore out and would not pull the plunger back far enough to open the door.

Removing the screw was no help in this case, but I did later replace it with a new 5/16-24 stainless screw from Ace Hardware. I did grind the end shorter so it would not stick up. Then it took several tries at aligning the inside handle so it would not catch on the frame when opening the door.

I had to make a special piece of flat stock to slip in between the latch and frame and released it much like using a credit card, but in reverse.

I called Perko and they sent me a new METAL 2 piece camset FREE. Great folks.
A quick rebuild and it's good as new. Thanks Perko!!! 305.621.7525