What's the best way to secure a slipfit 1/8" steel gage pin into blind-hole steel?

[cazclocker]

If you don't need a press to install the gage pin, it IS a slip fit. Use the Loctitie.

Yes, my piece fits loosely enough that I don't need to press it in, but it doesn't have any lateral "wiggle". It seems to be a slip fit. I was unclear exactly which Loctite to use, but then Bone Head weighed in...

I've used Loctite 609 for things I want to stay secured. Good stuff. It seems to "wick" into the joining.
Whatever you wind up using good luck!

Ah... I came back here wanting to ask WHICH Loctite to use... and you just gave me that missing piece of the puzzle! Thank you!

O have used cyanoacrylaqte to secure a drill bit to an extension shank. I neck down the drill and drill a mating hole in the extension. A few drops of cyanocrylate in the hole and a rapid assembly and it's secure, able to withstand the drilling torque.

Wow... I'm amazed it survives the rotational torque of drilling. May I ask which brand of CA glue you used?

 

[Ulma Doctor]

I don’t know the loctite #s off the top of my head, but the red , green, purple are all high strength.
I prefer the red when in doubt

 

[WobblyHand]

For CA I used Bob Smith #103 I believe. Very fluid, seeps in well. I got mine from Amazon, although others carry it. When I bought it a couple of years ago it was about $8.50 for a couple of ounces. It's lasted quite a while, so can't complain. CA will loosen with heat, but otherwise is quite tenacious.

 

[cazclocker]

I don’t know the loctite #s off the top of my head, but the red , green, purple are all high strength.
I prefer the red when in doubt

Yeah I've tried and tried to understand the range of Loctite products. I'd need a couple of semesters at Loctite University to get it.

For CA I used Bob Smith #103 I believe. Very fluid, seeps in well. I got mine from Amazon, although others carry it. When I bought it a couple of years ago it was about $8.50 for a couple of ounces. It's lasted quite a while, so can't complain. CA will loosen with heat, but otherwise is quite tenacious.

Never heard of Bob Smith super glue - I'll have to look into it. Thank you!

 

[WobblyHand]

Yeah I've tried and tried to understand the range of Loctite products. I'd need a couple of semesters at Loctite University to get it.

Never heard of Bob Smith super glue - I'll have to look into it. Thank you!

Actually, me neither. But it works ok for me.

 

[dbb-the-bruce]

I went through this exercise a while ago and it really wasn't that hard to figure out which loctite to use with this chart

Basically, choose wicking, strong, removable or weak - then check the details for specifics. What you will find is that the more exotic types are not available at the box stores and even some of the more typical machinist tool/supply dealers.

It's pretty easy to just pick the cheapest commonly available one that looks like what you want. I sure don't remember the numbers. I ended up with the "green" 290 because it was wicking and on the shelf at the local store. Worked great. I'm sure the lower strength would have worked also but would have been mail order from one of the big-book companies.

 

[cazclocker]

The Bob Smith Adhesives website has a feature that lets you ask questions, so I did. I described my project and asked which of their products they would suggest. I haven't heard from them, but if they have a suggestion I'll probably order some.

In the meantime, I've ordered some Loctite 638; should be here Saturday. I settled on 638 by using the "Looking for a product?" feature on Henkel's website.

My selection process was:
Product Category = Retaining Compounds
Substrates 1 = Metal: Steel
Substrates 2 = Metal: Steel
Brand: LOCTITE (this was an irrelevant choice because by then all the choices are Loctite products, but what the heck, might as well)
Physical Form: Liquid
Cure Type: I ignored this choice because it wasn't going to affect the outcome at that point.
Key Characteristics: Ignored this one also, because I was already down to two choices.
Applications: For Slip Fitted Parts
Color: Who cares? Just ignore this. Actually, I'd pay double for any Loctite product that comes in polka dots.

That process led me to 620 and 638. So I selected both products for "Add To Comparison" (you can compare up to 4 products), then I hit "Compare 2/4". That took me to a side-by-side comparison of 620 vs. 638. Here's where I picked 638 over 620.

The two products seemed very similar. The fixture times are 620 = 60 mins vs. 638 = 4 mins. I don't care about that. The other big difference is shear strength, which I don't care about either because the only force being applied (when I use the gizmo I'm making) amounts to pushing the gage pin into the blind hole. Even the Gap Fill rating is the same... 0.15mm to 0.25mm. I don't know why "Gap Filling" is mentioned in 620's characteristics but not in 638's characteristics. They're both retaining products, and they're both for slip fits. The 620 product is for high temperature applications, but that doesn't seem to be relevant.

In the end, I assumed either one was going to work just fine. I let a coin flip decide for me.

I think I just don't know much about machining and I like to figure out how to do things in a manner that is as well-thought out as I can. Seems to be the way I'm wired. Sorry if I seem like a strange guy to you all!

 

[dbb-the-bruce]

Sorry if I seem like a strange guy to you all!

Don't worry, you fit right in with a large number of us....