Terminal Screws for Kraus & Naimer Switches - MEP-803A

[jungleboy]

First post - great forum, very informative and helpful. I recently purchased an MEP-803A and have been working on it, renewing insulation, pest-proofing, cleaning connections, repairing fuel tank leaks, replacing all rubber in fuel system, hundreds of SS screws, washers and nuts. Forum has been helpful for installation of VR upgrades and lots more. I have hit a dead end - I pulled off the rear upper cover panel and was not too happy about surface corrosion evident on some terminal screws.

I am looking for the terminal screws for the Kraus & Naimer switches such as S8. Apologies in advance if this has been covered, but I have reviewed the forum and the TM and have not been able to find an answer. The manufacturer website did not offer any tech data on older switches that I could find.

I believe I would prefer a corrosion resistant alloy if available and advisable, and have determined (I think) they are 4mm-0.7x8mm (steel) with a 10mm x 8 mm rectangular, curved captive washer that looks to be stainless. Short of pulling and cleaning the old steel screws, is there a better alternative?

Thanks & cheers

 

[Guyfang]

Since that part is a non repairable part, and the switches also, the parts will not be called out in the TM. I would call Kraus & Naimer and ask for information. Be nice, and butter them up!

OR, place a "parts wanted" add in the SS forum. I would plainly state that you are looking for a BAD SWITCH, to use the terminal screws. Someone may have a switch in the junk pile.

OR, take a screw to the local nut, bolt and screw source. There has to be someplace near you, or look on line.

If you want to try placing a want add in the forum, simply change this title on the thread, tell me, and I will transfer it to the proper forum.

 

[Triple Jim]

Those screws don't look very corroded... they just look a little discolored. I don't think I'd be concerned about them at all.

 

[Tinstar]

As already mentioned, those look discolored with age but not corroded.
Some elbow grease and Scotch-Brite will make those look new.

 

[jungleboy]

Since that part is a non repairable part, and the switches also, the parts will not be called out in the TM. I would call Kraus & Naimer and ask for information. Be nice, and butter them up!

OR, place a "parts wanted" add in the SS forum. I would plainly state that you are looking for a BAD SWITCH, to use the terminal screws. Someone may have a switch in the junk pile.

OR, take a screw to the local nut, bolt and screw source. There has to be someplace near you, or look on line.

If you want to try placing a want add in the forum, simply change this title on the thread, tell me, and I will transfer it to the proper forum.

Thanks for the replies. Good idea on calling K&N - will do that to see if they have a more corrosion-resistant screw available. If so will report back to forum in case anyone else is interested.

Don't want more of the same screws - they will clean up OK -but looking for a "lifetime" solution. Captive washer is a nice one, would prefer to keep these if possible. I think I can easily find brass or SS screws but would have to use common washers

Since that part is a non repairable part, and the switches also, the parts will not be called out in the TM. I would call Kraus & Naimer and ask for information. Be nice, and butter them up!

OR, place a "parts wanted" add in the SS forum. I would plainly state that you are looking for a BAD SWITCH, to use the terminal screws. Someone may have a switch in the junk pile.

OR, take a screw to the local nut, bolt and screw source. There has to be someplace near you, or look on line.

If you want to try placing a want add in the forum, simply change this title on the thread, tell me, and I will transfer it to the proper forum.

Thanks for the suggestions. Good idea on calling K&N - will do that to see if they have a more corrosion-resistant screw available. If so will report back to forum in case anyone else is interested.

Don't want to purchase more of the same screws - they will clean up OK - but looking for a "lifetime" solution. Captive washer is a nice one, would prefer to keep these if possible. They cannot be removed from screws and installed on new screws without a LOT of hassle. I think I can easily find brass or SS screws but would have to use common washers.

Forgot to add, the screw pics I posted are "after" cleaning with brass wire brush.

While taking out additional screws, saw indication that these screws, or at least some of them, may have been copper plated originally.

 

[2Pbfeet]

Could yours have been yellow zinc (chromate) plated?

https://www.amazon.com/PZRT-Terminal-Screws-Washers-Galvanized/dp/B09Q35V9G7

If it were me, I'd toss them in a vibrating polisher, wash them, and then hit them with WD-40 followed by Deox-It. Unless you get salt water on them afterwards, you would be good for a long time.

Do you know the screw size? If so, you could Google terminal block screw washer... I can't find many choices in SAE, but there are some out there, mostly in nickel plated.

All the best,

2Pbfeet

 

[Chainbreaker]

First post - great forum, very informative and helpful. I recently purchased an MEP-803A and have been working on it, renewing insulation, pest-proofing, cleaning connections, repairing fuel tank leaks, replacing all rubber in fuel system, hundreds of SS screws, washers and nuts. Forum has been helpful for installation of VR upgrades and lots more. I have hit a dead end - I pulled off the rear upper cover panel and was not too happy about surface corrosion evident on some terminal screws.

I am looking for the terminal screws for the Kraus & Naimer switches such as S8. Apologies in advance if this has been covered, but I have reviewed the forum and the TM and have not been able to find an answer. The manufacturer website did not offer any tech data on older switches that I could find.

I believe I would prefer a corrosion resistant alloy if available and advisable, and have determined (I think) they are 4mm-0.7x8mm (steel) with a 10mm x 8 mm rectangular, curved captive washer that looks to be stainless. Short of pulling and cleaning the old steel screws, is there a better alternative?

Thanks & cheers

View attachment 911831View attachment 911833

Larry, Moe & Curly's expressions in the background picture you used seem to suggest to... "Screw it, those just need a little TLC!"

 

[Guyfang]

K&M switches are very good switches. I would not worry about the screws. If I had not quit my job 2 weeks ago, I would go dig up a used switch and send you the screws. But they may look just the same.

 

[NY Tom]

Here is one similar from Misumi.

You will need to buy a lot of them but the price is not out of reach I guess.

The company I work for sells them as well but only on #6-32.

 

[jungleboy]

K&M switches are very good switches. I would not worry about the screws. If I had not quit my job 2 weeks ago, I would go dig up a used switch and send you the screws. But they may look just the same.

Thanks for the sentiment - upon cleaning, I see no pitting, but 40-50% had noticeable corrosion.... Just cannot clean very well between screw and washer.

 

[jungleboy]

Here is one similar from Misumi.

You will need to buy a lot of them but the price is not out of reach I guess.

The company I work for sells them as well but only on #6-32.

I saw the Misumis but they are steel too.... was looking for some type of alloy. I did find nice Cu alloy ZnCr plated 6-32x7.78mm screws for relay sockets at TE - https://www.te.com/usa-en/product-1437651-6.html

 

[jungleboy]

Larry, Moe & Curly's expressions in the background picture you used seem to suggest to... "Screw it, those just need a little TLC!"

Nyuk, nyuk, nyuk.... Soitanly!

 

[NY Tom]

I saw the Misumis but they are steel too.... was looking for some type of alloy. I did find nice Cu alloy ZnCr plated 6-32x7.78mm screws for relay sockets at TE - https://www.te.com/usa-en/product-1437651-6.html

Nickel plated steel is standard for square SEMS screws. The purpose of the SEMS is only to keep the wire from turning as you tighten the screw. They force the conductor against the component that sends or receives power down the wire. Not designed to transmit the electricity directly although they are conductive. Since the items you mention are metric your choices are limited.

The nickel plating should hold up for a long time inside the genset if it was done correctly.

 

[Chainbreaker]

Thanks for the sentiment - upon cleaning, I see no pitting, but 40-50% had noticeable corrosion.... Just cannot clean very well between screw and washer.

Have you tried using the "Vinegar & Soda" trick on them? Worth a shot...

 

[Guyfang]

IF, you could find the right screw, with the right threads, made of what ever material you want, give me the data, and IF I can find them here in the land of metric everything, I would try and get them. Could not cost THAT much.

 

[jungleboy]

Could yours have been yellow zinc (chromate) plated?

https://www.amazon.com/PZRT-Terminal-Screws-Washers-Galvanized/dp/B09Q35V9G7

If it were me, I'd toss them in a vibrating polisher, wash them, and then hit them with WD-40 followed by Deox-It. Unless you get salt water on them afterwards, you would be good for a long time.

Do you know the screw size? If so, you could Google terminal block screw washer... I can't find many choices in SAE, but there are some out there, mostly in nickel plated.

All the best,

2Pbfeet

The half not corroded brown are greyish, so I assume zinc plating, although several corroded ones look coppery to me, where not corroded in the screwdriver slot. Maybe a mix of materials in screws on switch? For the time being, I have cleaned mechanically with brass brush, vibrated in soapy water, rinsed, sun dried and coated in Deoxit. Should last for a while.

 

[jungleboy]

IF, you could find the right screw, with the right threads, made of what ever material you want, give me the data, and IF I can find them here in the land of metric everything, I would try and get them. Could not cost THAT much.

Thanks - I could have used some local help getting seals for my Weber Hydraulik 30T jack last year!

I am looking for OEM type replacement. The issue I see is removing and reinstalling the curved washers. McMaster has a good selection of SS 4mm-7x8mm machine screws, and cheap.

I have a call in to K&N but no reply yet.

 

[peapvp]

They are correctly called in German:


Linsenkopfschrauben / Stahl-Klemmschraube (Kreuzschlitz / gerader Schlitz Combo Drive), mit Drahtkelmmscheibe, Edelstahl

they come in different sizes and Metalls
and according to the screw gods in metric land, they were invented during the Ming Dynasty (A.D. 1321 - 1466) and require the traditional Chinese Assembly method

Your best and probably only sources for those German Edelstahl Screw Wire Clamps is either Alibaba or AliExpress,
since they are now manufactured in one of the German Colonies in China
I am not kidding you.

 

[Guyfang]

I might also try and go back to the firm I just quit. I still have the key. The last two times I tried to quit, the boss told me to keep the key. Because if I keep it, there is a chance I will come back. We will see what happens this time!