Where do you get replacement bolts?

Hi All,

Something I've been struggling before but usually cheated myself out of by re-using the old bolts. Right now I'm replacing the water pump and really want to get good quality replacement bolts on the pump and the thermostat housing. Been to Napa, Home Depot, Ace, Kragen and none of them have the right sizes. Where do you order/buy them?

Thanks!

Tim

I go through mc master-carr and order extras

I get most of them from my local hardware store - since they carry SAE5, SAE8, CRES, and Brass - but I wish they'd expand their brass and CRES sections.

Specialty stuff I usually end up either going to Mr. Metric (they're local to me) or Fastenal (ditto.) Both Mr. Metric and Fastenal are online.

You might also want to get a catalogue from MSC direct - that's a boatload easier than getting one from McMaster (took me two years to get one, and that was ordering parts at about $40k/year!) and they seem to carry a lot more stuff useful to us. The MSC catalogue is free for the asking, and about the size of a New York phone book!

5-90

Thanks guys. So far I had no luck. What I can make of it the water pump is attached with 4 m8 bolts, one of 45mm and the other around 28mm length. The thread is 1.5 (not sure what the units are there (think mm) but I've seen them come in 1.0 1.25 and 1.5, and then sometimes the thread is refered to as standard/fine/course thread, which probably refers to the same ranges but again, I am unsure). At fastenal I couldnot find these. At McMaster they have 1.5mm thread only for m10 and bigger. Mr Metric sounds like it would be a better bet but their site is under construction. I guess I should seriously start considering cleaning my old bolts.....

Tim

If I remember correctly those are fairly standard SAE bolts. The length may be off some, on off the shelf bolts, but a nut to screw on the bolt and a hacksaw will fix that quick. Dress the end a little with a fine file or a thread file.
Grade 5 galvinized bolts are easy to find and will get the job done well. Or grade 8 anodized bolts will work, but are overkill. Any bolts into or onto aluminum usually take a pretty mild torque.
I replace those bolts most everytime I do a water pump, I've seen them seriously corroded on Renixes and snap off when trying to remove them.
I bought tons of military surplus nuts and bolts years ago ($30 ton). I've likely got hardware for a couple of generations and rarley need to buy any (SAE or Metric).
Me and the kids have spent many enjoyable winter evenings sitting in front of the fireplace, watching a video and sorting nuts and bolts, quality time:laugh:

You can usually clean your old screws with a wire wheel in a drill motor or a drill press. If I'm not going to use them straight away, I have a spare bowl for my brass tumbler, and they spend a day or so tumbling around in crushed walnut hulls.

As I recall, those screws should be either 1/4"-20 or 5/16"-18 - fairly standard stuff. If you can't source them in CRES, brass, or bronze, take an extra moment or two to coat the entire shank with a light coat of RTV Black - I don't like putting plain steel bolts (even galvanised) in potential contact with hot water.

The thermostat housing screws should also be 5/16"-18, but are two different lengths.

SCREW PRIMER -

"Inch" nominal screws can be called out in one of two ways - depending upon size:
(Number Sizes) - #10-32 x 1"
The "#10" denotes the nominal size of the screw (outside, or total, diameter.) (Corresponds to size by the formula (.060" + .013"N, where N is the number size.)
The "32" is the thread pitch (inch screws are always called out in threads per inch - so each thread is 1/32" from the next.)
The '1"' is the nominal length of the screw. Unless the screw is a flat head or an oval head, designed to go into a countersink, this is the length from the base of the head to the end of the thread. If is is a flat or oval head, this is the overall length of the screw.

(Nominal Size) - 1/4"-20 x 1"
This is as for the number sizes, except the nominal OD of the screw is given directly. Sometimes also called "fractional" sizes.

"Metric" or "ISO" screws are always called out the same way -
M10-1.5 x 40
"M10" means the nominal OD of the screw is 10m/m
"1.5" means 1.5m/m per thread (note that this is different from the callout in "inch" sizes - here, the thread pitch is given directly)
"40" means 40m/m nominal length (variations as above - total length for flat head or oval head screws, underhead length for everything else.)

DIFFERENTIATION OF SCREW TYPES -
"Inch" screws can generally be told apart by checking the head markings - if it has three "hash" marks in the corners of the head, it's an SAE Grade 5 (and therefore inch.) If it has six hash marks, it's SAE Grade 8 (and therefore inch.)

"ISO/Metric" screws will have a "property class" stamped into the head, which takes the form of "8.8", "9.8", "10.9", and the like. These are also the strength of the screw - but I'd have to look the markings up, since I don't refer to them very often (I typically use SAE screws, since I think in inches.) Of course, higher numbers are stronger - and more brittle.

The "hash marks" on SAE screws apply only to SAE-graded carbon steel fasteners. Screws made of other materials will have a "maker's mark" on the head (not to be confused with an ISO property class,) but will not have hash marks. CRES/Stainless Steel fasteners generally - but not always - have a three-digit section of the maker's mark which denotes the CRES alloy used, which is usually 303, 304, or 316.

5-90

There isn't much difference between a 5/16" X 18 X 1/2 head and a 8 MM X 1.5 X 13 MM head. The metric will start in the SAE thread hole ,but after a couple few threads will start to turn really hard and screw up the threads.
Like 5-90 mentioned, look at the head marking.

Cool! Thanks guys, and sorry about the metric mix up. I am a european lost in this country with its mystical measures. I tend to go metric when in doubt and I should have looked more careful. Sorry about that. Thanks for the help and explanation of inch size (5-90), that's really helpful.

Tim

That's funny - I tend to have an easier time with my "twelves" than my "tens" - curse of thinking in inches, I guess. I can convert, but it takes work.

As 8mud mentioned, the easiest way to tell the difference between an M8-1.25 and a 5/16"-18 is to look at the markings on the head - if you don't see something like the "property class" markings I'd mentioned, it ain't metric. I'm almost willing to bet they're all 5/16"-18 anyhow - just because they tend to change castings more often than they change tooling (what do you want to bet that the 2001-up AMC242 takes a 3/8"-16 hex head capscrew for the rocker pivots, just like the 1987 AMC242? They revised the head casting three or four times in between there...)

If I don't know what size the screw is offhand, I'll look at the head first on a hex head - just so I can start by sorting it into "inch" or "metric."

I plan to do a "basic screw primer" page on the WiP site sometime (hopefully) in the near future - you might want to watch for it. I'm trying to demystify a lot of what's going on under there, so you all can work on it easier...

5-90

dutchjeep said:

Cool! Thanks guys, and sorry about the metric mix up. I am a european lost in this country with its mystical measures. I tend to go metric when in doubt and I should have looked more careful. Sorry about that. Thanks for the help and explanation of inch size (5-90), that's really helpful.

Tim

Click to expand...

U still working on that water pump...what is wrong with the old screws? They don't usually get wasted in Cali..

Water pump's done. Runs like a dream, no leaks and much cooler (it used to run 200-210, now it's closer to 185-195). Surprisingly it also runs slightly lower in revs when idle and starts easier (less cranking). Although this is basically a good thing (the starting in particular) I don't understand why just replacing the water pump and thermostat would accomodate that, but it really seems that way.

Basically there was not much wrong with most of the screws. Some where rusted (mostly those on the thermostat, not on the pump) but on the pump one thread was worn pretty bad (came out ok, but not very smooth). It's just I read so often that when doing a job it's best to replace all the screws with new ones. Therefore I decided to upgrade my trade and replace the screws if I could. So that's where all the confusion came from.....I was doing something I never done before. I tend to that a lot (things I never done before) so I am generally pretty confused.

I ended up replacing the short screws on the pump and both the screws on the thermostat housing. Not sure if it was needed, but it looks nice (shiny new screw caps) and feels good. I didn't replace the long screw on the pump since my replacement screw was slightly shorter (maybe 1-2mm, clueless what that is in inches) and since the old screw still looked ok, I went ahead and used that one.

I don't know what the general strategy should be when it comes to replacing bolts. It was a good learning experience anyway, which is always helpful I think. Any ideas/suggestions on replacement strategies are very much appreciated!

One more thing I noticed is that standard washers in the hardware store are wider than the ones on the screws on the car. What do you guys use there? Just go with the slightly wider ones if they fit? You do need to use washers right?

Also when do you use loctite, never seize or and RTV sealant on screws? What's the strategy there?

Thanks again for all the help guys! I'm glad the pump's back and my little green friend is humming me to work again! I truly enjoy learning this stuff and appreciate the time and input I get from all of you!

I tend to replace screws anytime I'm either working undercar (subject to rust, road crud, and general crap anytime I'm working with water (usually with CRES or brass, so I don't have to worry about them anytime I'm working on something highly stressed (cylinder head screws, suspension,) or anytime I'm pulling out an original screw (my newest rig is a 1989 - so they're 17 years old.)

If you can't source CRES (stainless - Corrosion RESistant alloy) locally, and you're in a hurry, you can use RTV to lightly coat the screw against rusting/water exposure. Coat from the bottom of the head to the end of the screw. There is no need to alter your torque setting.

Loctite is something that should be used generally on screws - unless it's something you're likely to adjust, or is likely to stretch (leaf spring U-Bolts come to mind here - I use Nylock nuts for those.) Loctite does not alter the friction of the screw, so no need to change torque settings there, either. There are several different grades of Loctite - select carefully.

Teflon pipe dope is only used on one screw - #11 (AMC242) or #8 (AMC150) cylinder head screw, since it penetrates the water jacked. It alters torquing slightly - specs for that are given in the manuals, and on my website.

Never-Seez is more of a "tool" to me than a "thread treatment" - simply because using it reduces installation torque by half as opposed to "clean, dry" threads. For instance, the axle hub nut torques to 175 pound-feet. With never-seez, torque it to ~90 pound-feet. Never-seez comes in two varieties that I know of - aluminum/nickle base (silver) and copper base (gold.) There are probably others available, I've just never needed them. I use copper-base anywhere a screw is going to be subject to great heat.

Washers are something I prefer to use wherever possible - since it increases the bearing area of the screw head.

Please, when you replace any screws, write down what you replaced, what size you replaced it with (if OEM,) and your vehicle particulars - then email that to me here at 5-90 AT naxja DOT org. I'm compiling a listing on my website, and I need all the information I can get. Especially for 1991-up models!

Bear this in mind -
Torque specifications given in manuals (and on my website!) are, unless otherwise specified, for "clean, dry" threads. If you need to torque the screw, clean it first.
If you oil or grease the screw, reduce the torque value by one-fourth
If you use never-seez, reduce the torque value by one-half.
If you use RTV, use the full torque value
If you use LocTite, use the full torque value
If a lubricant is specified (engine oil, Teflon paste, or whatever,) use the specification given with the lubricant specified only.

5-90

Thanks 5-90, for your explanation. Will try to use that as a giude in the future.

If I do any future screw replacements I will let you know. Probably not a good idea to take those into the compilation before you check though. Remember, this is the guy that tried to install his water pump with M8 1.5 bolts!

Take care,

Tim