old bolts

[imported_fordmerc]

I need comment on bolts removed. After cleaning and bead blasting many are obviously pockmarked with rust pits, mostly the size of pinholes. How bad do they have to be before they are no longer reusable? What can be done to prevent re-rusting if they are again installed? How to preserve present appearance ( nice fresh, clean metal - except for rust pits) My concerns are safety, originality, and appearance, in that order; I can settle for a driver rather than show.

[Peter J.Heizmann]

John...welcome to the forum...

To answer your query, more information is required.

Where are the bolts utilized?

Metallurgy has a lot to do with it. Are they stainless, steel, etc.?

After bead blasting, the pitch of the bolt threads could have been altered to the point they will not be accepted by the pitch of the return area.

Pitting...I can only assume they are steel rod bolts and internal oxidation could be hidden, although, the exterior looks decent.

Do your best to respond with more info...

Regards, Peter J.

[imported_fordmerc]

Thanks for response. Bolts are original '39 Merc. The question was generic. Current bolts in question are brake backing plate, spring U-bolts and other chassis assembly bolts. I assume "steel". 35 years of surface rust looked a lot better after the "blast"; chemicals just didn't work. I'll replace for safety if necessary.

[Bill Stoneberg]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"> I'll replace for safety if necessary </div></div>

Hi John,

I would and normally replace any and all bolts for my own piece of mind. I would rather know that a bolt wont break on my suspension, springs or numerous other places then take a chance on 50 year old metal.

In the grand scheme of rebuilding cars the cost is minimal while the risk of not replacing is too high.

My 2 cents worth and welcome to the forum.

[48LCCOUPE]

I will throw in my uneducated opinion here. If they are chassis bolts, nuts and screws that are simply pitted, I would not worry. If they didn't break, bend or fracture when being removed, then they are good candidates for re-use. If a bolt has actually eroded, rusted to the point of eating away an amount that can be related in simple fractions when looked at. i.e. 1/4, 1/8, 1/2 then throw that sucker far from the vehicle(on second thought, discard in trash as you would otherwise run over it and flatten a tire, old bolts go down fighting). If it were engine related bolts requiring torque settings to be attained and maintained which also can cause stretching of the bolt / screw, or hardware that finds itself in or near water jackets and such, replace.

I like to coat threads with anti-sieze. It aids in future removal and I believe provides at least a little protection. It does NOT in my opinion cause hardware to loosen over time, and I am not sure where or how that rumour got started. A can or jar of anti-sieze around will make a friend of the next guy that decides it's time to tear it apart and reassemble, and if that someone is you, you can thank yourself later.

[D Binger]

John,

If you have any question at all about the serviceability of any bolt, you should replace them. Your life is worth a lot more that a few dollers for new bolts.

Dan

[palbuick]

Hi

The Eastwood co. has a kit for blackening bolts and other brackets , that were originallly blackened at factory. I believe you can find the kit on line.

Jim Schilf

palbuick@aol.com

[Guest Ken G]

I just have to add how easy you all make it sound. You casually say "if in doubt, replace them"! With the only one in North America of a British vintage car model whose threads are of course BSF and Whitworth, replacing bolts is difficult, time-consuming, expensive, and sometimes impossible. I am largely forced to re-use the old bolts. Fortunately so far, I haven't found bolts that were seriously damaged.

Ken G, 1925 Rover 16/50 (San Francisco)

[Ron Green]

You can also have the bolts cad plated fairly cheap if in fact they are safe. Its nice to be able to use a wrench without taking paint of a bolt, nut, etc. I have used Charles D Snyder & Son in Harrisburg PA at 717-234-7047 a few times. It cost me around $150 for a fair amount of bolts, brackets, etc and they offer a hi and low shine.

[Guest stude8]

I wouldn't trust any "Modern" replacement bolts I could avoid by using the "Real Steel" used in prewar bolts. Every fastener carton you find has a disclaimer notice that they can't even tell for sure where and what they are made of (China, Bulgaria and others that aren't even in my atlas yet).

How many prewar 3/8" hex bolts can you twist the heads off? Put serious torque on the recycled scrap metal "New" bolts and see what happens.

It was only a few years back that unscrupulous vendors were selling bogus "Grade 8" bolts that got used in aircraft landing gear applications, a sharp technician asked for verification of metal content and it ended up with a Federal investigation.

Stick with your good old American hardware made when you didn't worry about who you were buying from, they were all reputable suppliers. Stude8

[DizzyDale]

Dear John,Roy Nacewicz in Michigan has all new hardware for Fords and

Mercurys in kit form and in the correct finishs.Phone #is in Hemmings.diz

[John N. Packard]

I've used the cold blackening systems from two vendors and find that the bolts tend to rust in a few months. So, I paint everything and they do chip on installation and/or subsequent removal. I haven't really found a satisfactory approach to restoring fasteners.

jnp

[Jack Harlin]

Very interresting topic as Im preparing to paint a 53 Packard engine with

rusty head nuts. 7/16X20, 3/4 " OD. I never thought they were so hard to

find. One vendor had them, but like Stude 8 said, I asked where made, but

didnt know. Chrome acorns are available, same answer. A machine shop had them

but did not recommend using them with tourque reading of 60 to 65 lbs.

A well known Packard vender said if you find them he would buy them out???

Im going to put them on all thread rod or bolt, blast them & wire brush

the ends.

Ron Green. Didnt know Snyder still in business. George chromed a 38 Super

grille for me in late 50s. Jack

[Rich Niezabitowski]

A trick I learned form an "old-time" Model A person was to paint a stripped steel bolt with High Temperature paint, such as VHT. It looks surprisingly like real black oxide coating, which is done by dropping a heated bolt in oil. If you store the bolts in Automatic transmission Fluid, they will not rust. When you go to use them, claen off the ATF and they look good and seem to last a long time.

Ther was a post up the thread about British fasteners. As owner of a 1958 Austin Healey, all I can say is amen. If you restore an LBC (Littele British Car) as we call them, you learn to restore bolts as NOTHING is really available as they are all special.

[Guest stude8]

I thought I would add this direction to go, there are sources for real original NOS hardware, rare but for me I found that the Studebaker factory inventory that still exists in South Bend (SASCO, 410 W. Sample St, 46601) has barrels of bolts on hand, the trick is knowing the factory part number for the size you want.

I needed a set of 1/2-13 x 2-13/16" high crown cylinder head bolts for my 1930 President engine rebuild (NLA) and found that a 1935 bolt of the same size was on hand. They cost almost $4ea but were the real thing, no Taiwan involved.

They used to have the common 5/16" & 3/8" sizes in NF & NC in bins, pick out what you wanted and sold by weight $1.50/LB. They were forced to relocate due to the city condeming the 1910 building to make way for a new jail, the moved tons of material to a new location across the road, don't know how much hardware survived the move. Stude8

[Guest JT]

Jack, I am just finishing up a rebuild on a 120 and although I used new studs I reused my head nuts/washers since they seemed in good condition with no pitting. I did soak them in a metal prep and then sprayed them with a high temp paint. I also coated studs with anti-seeze to help prevent corrosion to head. Once iI have done my final torquing I will paint them Packard green to match head.

[Peter J.Heizmann]

Folks, below, I cut & paste a "Bolt Strength" study I performed in Dec. 2002 to assist queries from Stude8 concerning "bolt strength". When you read the metallurgy results of the 3 specimen bolts I utilized in tests of micro-structure, for whatever reason, the columns did not remain in a clear order.

Look at the sample headings used when you get to the micro-structure area:

"TEMPERED" -- "GRADE 8" -- "GEORGE'S SAMPLE"

"You will see a noticeable difference from an original bolt that George supplied for the test. "KEEP THIS IN MIND WHEN DECIDING TO USE AN OLD BOLT OR GOING WITH A REPLACEMENT". -- "SAFETY!!!

(IT WAS A DESTRUCTIVE TEST..."PAY CLOSE ATTENTION WHEN YOU READ THE TORQUE SHEAR POINTS TEST" AREA...YOU WILL NOTICE THAT GEORGE'S ORIGINAL BOLT METALLURGY DOES NOT CUT IT IN SAFETY RELATED APPLICATIONS OF TODAY'S BOLT!!!)

________________________________________________________________________________

Re: Bolt strength

#140989 - 12/18/02 07:55 PM Edit Reply Quote

This is going to be a "long" one folks. I will start, with due respect, to George Rohrbach, who, made the initial post/query. In decending order, I post direct/simple opinions of "old" bolts vs. "modern" manufacture. Afterwards, the technical findings of the study, again, in decending order.

George:

--Go with Grade 8, or, other Tempered Bolts and Nuts for replacement on steering, tie rods, etc. applications. Your sample of a 1920-30's era bolt failed convincingly compared to Grade 8 and the jh Tempered Bolt. As Bill Stoneberg posted, Grade 8, or, other good Tempered Bolt.

--85,000 p.s.i. is normally for internal pressures for pressure vessels. Brinnell Hardness, or, a Rockwell Scale reading is the question: Again, replace with a high Grade/Tempered bolt.

--Bolt Head Dimensions:

(Did not use a Stainless bolt, as I personally would not use them for steering applications)

Tempered Bolt: .532

Grade-8 Bolt: .534

George's Bolt: .539

--Brinnell Hardness of the Tempered jh Bolt tested was first: 327.5-344.5

Brinnell Hardness of the Grade-8 Bolt tested was second: 293.5-310.5

Brinnell Hardness of the 1920-30's Bolt tested as third: 258.0-271.0

--Torqued Shear Points of the 3:

Tempered jh Bolt: Withstood 200 ft. lbs.

Grade-8 Bolt: Withstood 200 ft. lbs.

George's Bolt: Sheared at 147 ft. lbs.

(These bolts were all bolted down into tool steel with the heads flush to the surface.)

--JB-ed posted: "the Head Size was reduced about the same time bolts were "Graded" and would it have any affect on strenth?" in so many words:

Not in my opinion. The measurements of George's bolt head (.539)to the lowest measurement, the Tempered Bolt (.532) is miniscule, although, we are not creating a Space Shuttle here. We are looking at a difference of .007. The millage of the coatings could be just the difference.

--De Soto Frank posted: "...TRW joints included grade-8 hardened bolts in lieu of rivets". THAT ALONE SHOULD TELL YOU SOMETHING WHEN REPLACING BOLTS ON SUCH A SAFETY ITEM. The study I found sure backs it up, folks.

--Now, the chemistery findings:

(NOTE: Copper I found to be "Residual", meaning, it was present in either re-cycled metal, and, passed along to the bolt when it was produced.

Moly (Molybdenum, Mo) The Grade-8 Bolt appears to have been intentionally inoculated with Mo with a reading of .20. The Tempered Bolt had .02 and George's Bolt had .00, so, they read as residual. THIS BACKS UP BILL'S AND FRANK'S INPUT, THAT, ONE SHOULD USE A HIGH GRADE. 8 IN THEIR EXPERIENCES.

Here we go:

Grade 8/ Tempered/ George's Sample

Carbon © .39 .40 .35

Silicon (Si) .21 .23 .16 (Look out, folks!!)

Phospherous (P) .008 .012 .007 (Low)

Sulphur (S) .012 .011 .024 (Air Quality back then??)

Manganese (Mn) .73 .69 .64

Nickel (Ni) .02 .02 .01 (Low)

Chrome (Cr) .99 .10 .09

Copper (Cu) .01 .01 .05 (ALL 3 RESIDUAL)

Molybdenum (Mo) .20 Intential .02 Residual .00 (Non-existent)

Magnesium (Mg) .00 .00 .00

--Bottom line, go with Bill Stoneberg and Frank's advise...Grade-8 for replacement.

--This is one of those posts you hate to "hit send" in the sense that the "Legal Beagles" could rear their heads, however, the study was done on ISO Certified Spectrometers, and, Gauges, all of which, have been Certified within 4 days. IT WAS PERFORMED TO HELP STEER HOBBYIST'S IN THE RIGHT DIRECTION CONCERNING SAFETY ITEMS.

Hope some of this helps...bottom line, do not fool around with cosmetics of a bolt without knowing what is under the o.d.

Regards, Peter J.

[DRH]

A good source for very good quality bolts is your local CAT dealer.All of their bolts have cat on the heads.The heads are thicker just like many pre-war bolts.If you remove all head markings you will have a thick head bolt that will look correct for you pre=war car and be very strong,Don

[48LCCOUPE]

Cat also requires all suppliers to meet their specs. If it's a Cat grade 8 you can belief it's that and then some. They have a full time testing system and lab that randomly tests all shipments. random and all? oh, you know what I mean

[Peter J.Heizmann]

Dave and Don...interesting comments.

The study I performed on George Rohrbach's old Studebaker bolt was to compare "strength and cosmetically improving" a 70 year + bolt, versus, what is available today, comparative metallurgy, and, so on. To grind off bolt head markings to make them look pretty is fine, in my opinion, for show purposes. To replace them in a safety application can be disasterous if you assume the bolt should work as it is brand new from the "el-cheapo automotive stores" out there.

If it is a non-load atmosphere and the bolt looks good, go for it.

If a Safety atmosphere after 70 + years, use common sense...

Glad to see CAT, and, probably other OEM folks are doing spot checks...what scares the hell out of me is the run of the mill Auto Stores out there today, of which, practically everything they display has been manufactured by offshore vendors somewhere within this fragile earth, that, could not care less about our DEP, Air Regulations, etc...

It all gets back to economy, the jobs that were lost within this country, the almighty $$...the gent that alluded to the Air Force aircraft "ductile" bolt scenario above...well, they were made in China, where all our jobs within the metal working industry are headed, or, have gone. Ductile is an alloyed iron. To cheat on its metallurgy could only be attested to by the Titanic passengers. (The ships plate was a "cheap/rushed" supposed ductile". In cold atmospheres, ductile becomes "brittle" and could literally shatter.) Our air-pollution boys within the U.S. of A. have not the guts to take the initiative to enforce the same regs on them. (Unfair of me. They probably could not care less!!.) Until then, keep cosmetically improving an "ancient bolt", or, "buy from China, India, and, the Pacific Rim in general.

Peter J.

[Ron Green]

As far as I know Synder's is still in business. Recommend that you wire brush your stuff first to get a better job. I had to send a few things back that they got a little lazy on in regards to cleaning before plating. That said the hardware I sent over did turn out good except some of the bolts that were pitted bad. I put them where you really had to look. They were very cost effective for using all the orginial bolts, clips, brackets etc when compared to painting or using hardware that just did not look correct.

[John N. Packard]

There is considerable discussion on this thread concerning the safety of using old bolts. Does anyone have real life testimony of failures they experienced as a result of reusing old bolts and/or stainless steel bolts or foreign made?

jnp

[Guest JT]

John, good question, that's what I was wondering.

[48LCCOUPE]

No one alive to tell about it.

[John N. Packard]

So let's take a census and find out who is missing!

jno

[1913Moline]

Cat does use all high tensile strength bolts, although all new designs are metric (that is my day job). One thing that you wont find anywhere within Caterpillar is a lockwasher. I regularly re-use old bolts, even in very critical bolted joints within engines, but I ALWAYS replace the lockwashers with hardened flatwashers. Whether rebuilding a flathead Ford, or a straight eight Packard or Pierce, you should never use a lockwasher on a head bolt or stud. The bolted joint requires bolt stretch, and a lockwasher will give an inaccurate torque reading and an improper clamp load on the head gasket, exhaust manifold gasket or other critical joint. Sure they worked when they were new, but if you just spent thousands of dollars on a rebuild, why risk the mess of a blown gasket.

As far as strength of cheap import bolts- even a Grade 2 bolt has a tensile strength of 50,000psi. A grade 8 bolt will exceed 160,000 psi tensile strength. The reality is that most bolted joints on a car dont require a high tensile strength bolt. Wheel studs, head bolts, main bearing bolts, spring shackle bolts, rod bolts etc. are places to be careful.