Sometime ago there was a topic talking about bolt markings and strength and such. I ran across this YouTube channel awhile back and saw this. It will answer any questions about the markings mean and how they measure out as far and strength and hardness go.
I really dig these guys. Awesome content.
I cringe any time I see anything less than grade 8/ 10.9 (hardware store bolts) on any machine.
Some times a grade 5 is better when you don't want it to fail with a bang.
Use the grade and material that the application calls for.
I like the grade 5 for sheet metal and non load carrying stuff. It's easier to drill and easy out.
Grade 2 for shear bolts.
Watched the entire video, and was what I previously read in a book written by Bouwman bolt makers about 30 years ago. Good amount of detail, and well made video. Glad you shared it. Simon C
I personally use a lot of gr 5 for general applications, gr 8 for anything critical, gr 2 for shear bolts, or if I need a lot of bolts to hold wood together. Otherwise, if I find a gr 2 or 307a bolt around my shop, I throw it away. This is mostly an old habit from the days when I had lots of employees. What I learned from this video the first time I saw it was about the stainless bolts. Since I work with fertilizer so much, I use a LOT of 18-8 bolts. If a gr 8 bolt is going to lose 50% of it's diameter in a year, it's definitely not stronger. You also won't unbolt it next week. I always thought the 18-8 was about the same as gr 2, so I tried to upsize it where I could. This video showed them to be about the same as a gr 5, which matched my experience, so I relaxed about them somewhat. Also, I have noticed a few of those Bouwman bolts over the years, but I didn't really know what they were.
Some people refer to the Bowmalloy type bolts as grade 12 but that's not an official grade. The bolts sometimes referred to as grade 9 isn't an official grade either. There was a discussion about that quite a while ago. I think Cat bolts are in this category but referred to as exceeding grade 8. For things like a temporary tooth pin grade 5 are better because they bend instead of snapping. I was good friends with the manager of Bowman in Edmonton. He retired after 47 years and Bowman didn't really do much or give him anything for his many years of service. He started in the warehouse packing customers orders and worked his way to the top. Super nice guy. Bowman was a little pricey but very high quality stuff. I went to see him once on a Friday and it was past closing when a customer knocked on the door looking for a HD battery cable crimper for his Cats. Instead of turning the customer away, he went in the back and got the crimper and connectors the guy needed and put it on the customer's account. I know a lot places would have just said we're closed and to come back on Monday when we're open. He offered to send out news letters for the MX club no charge and Bowman had a postage machine to make it easy. He covered the cost of the postage. Figured it was a small way to help the non profit club. I haven't spoken to him in about 12 years but just looked his name up and am saddened to see he passed away from pancreatic cancer at 74. Rip Jim. His wife raised and showed sheltie's and had the top sheltie in Canada. It got hit by a car when with someone else. She had another top sheltie she sold for $14,000!
The Bowman Fastener Facts book from 1989, that Simon mentioned, is an awesome resource. It was updated a couple of times, then it disappeared. I adopted it as a text book when I was teaching. There are pdf copies available on the interwebs.
On a lot of new farm machinery there using a smaller bolt of higher grade so that it snaps cleaner and doesn't smash its self to the point of being difficult to remove
Our unloading auger at the farm is this way. Its a pto driven, 60 ft long, 10" auger with a truck unloading hopper attached. 100hp tractor to run it, a single grade 5, ⅜" bolt for shear protection. When it pops, its a nice clean break. Clean enough that I'm usually able to find both halfs laying on the ground underneath the pto shift area which let's me reuse the lock nut. I think we went through 5 shear bolts this year, but the same lock nut every time. It's a special shaped lock nut so its worth finding as a nylock won't fit in the slot it has to set in.
I saw a sales rep for Bowman make a big presentation at the maintenance conference at the University of Washington back in the eighties. He did a similar thing with a hydraulic machine and a torque wrench to demonstrate the yield strength of various bolts in a small size. The Bowman bolts were very good but didn't make any sense in the heavy equipment industry. The unit cost was way out of proportion when compared with a simple grade 8 bolt. It was a great presentation more in line for people working in the aerospace industry, meaning Boeing. The majority of the people attending the conference at that time were about two steps out of being blacksmiths.
If any equipment repeatedly breaks bolts, there is a problem with the equipment, or the operator. Hard to imagine a situation that would be solved by installing exotic super strong bolts.
The Bowman guy said that. Another statement was that a properly torqued bolt in a properly designed application will not come loose therefore all lock washers should be sold and never used. When I started in this industry there were a lot of single very large fasteners requiring huge sockets and wrenches. Now everything is held together with lots of small bolts.
Thank you for posting this.
I tend to agree in most applications. When vibration and/or flex is involved is where I find bolts and regular nuts tend to come loose. I try and use stovers or nylocks as much as possible. I'm not a fan of split lockwashers. I find they distort and spread apart often, usually when you have to hit the nut with the impact wrench due to lack of access to the bolt head. Nordlocks are becoming a favourite of mine. Kind of a PITA to bust the fastners loose, many times I have to use a breaker bar as the impact just doesn't quite have enough jam to get it over the first set of ramps on the washers.
Agree in principle but I still use split washers over flat washers and they do seem to add something to the stack. If they start to come loose there is still some tension being added by them.
This brings to mind dad talking about the bolts holding the backhoe on there international backhoe they had it would even break supertanium bolts.
One place that always seemed to be problematic for breaking bolts were scale pads on logging trucks/trailers. I think my dad was changing out all of them every breakup just as a preventive measure. Every time one would break it was a 1-2 hour charge from the local welding shop to extract it. Money ahead by just replacing all 20 every spring instead of heading to the welding shop 2 or 3 times a year.
One frequent problem with bots that won't stay tight is active length. Any bolt that has an active length (tension distance between the nut and bolt head) less than 2 diameters will be difficult to keep tight. 4 diameters is better. I have solved several problem bolts by making spacers to increase the length under tension. A properly torqued bolt is only stretched about .003"/inch of length. It doesn't take much movement between mating surfaces before dirt and paint relax enough for the tension to be relieved. The same can be true where one member is slotted. Without a flat washer, hardened in the case of grade 8 bolts, the stressed area under the head or nut isn't sufficient to support the load of the fastener. The video shows a abrupt loss of tension with the Bowman bolt. Metric grade 12.9 behave in the same manner. There are instances where the high strength but more brittle bolts such as those will fail in service where grade 8/M10.9 will work fine.
John C., I was at that same VMMC event at the UW. That’s where I got my Bowman Fastener Facts book. Before the tinnitus and sore back, when I was a bright-eyed youngster ready to make my mark on the equipment industry. Only mark I make in the industry was the skid mark on my BVD’s. I see where the trustees ended the VMMC organization this year.
Something that a lot of people overlook is the impact of the Fastener Quality Act legislation. So, I make sure I purchase my tanker hardware from places that provide lot traceability. Just in case a bolt-up fails and a spill occurs. At least I have a paper trail of where the hardware came from. YMMV.
I didn't know that. Their programs have been going down hill for a lot of years. The manufacturers didn't like a lot of the questions that were being asked and then they positioned it for government agencies like metro, big cities and municipalities. It's sad because I learned a lot from that conference back in the days that we attended.
Me too. It was awesome during the heyday. I got to present one year at the VMMC when Cat ACERT was introduced.
Vibration comes into play when bolts are suseptable to loosening. A lot of critical bolts on aircraft and things like race cars require safety wiring. There are even standards for safety wiring. Nordlock washers are a great option where safety wiring isn't practical. The distributor for Nordlock here told me even red Loctite can vibrate loose. Don't know what they were thinking when they designed the chain tensioner on my skid steer. It uses 3 5/8" fine thread Bowmalloy bolts with a length of 1/4" keystock welded to the bolt heads. If the chain gets too loose it will snap all 3 bolts if you try any heavy pushing. With the keystock welded on, the bolts have to be like glass just waiting to break. That's the biggest issue with the machine. Thankfully the mechanic at the dealer told me an easy way to check tension. With the proper tension there are no issues.
Some guys I work with swear by red loctite. I'm honestly not a huge believer. I find all it is really good for is making the bolt a massive pain in the rear to remove if the head strips (which is all too common on socket head bolts) or if the bolt breaks and needs to be extracted. Never really had an issue with bare bolts or anti-seized bolts coming loose if properly torqued.
Nordlocks are the best thing I have found for keeping PTO’s attached to Allison transmissions. Speaking of split rings, I don’t use them. Maybe they work for you. Fastenal, Bowman, Lawson,... are certainly happy to sell them. Two big reasons are: SAE says they don’t work. Caterpillar Power Division says they don’t work. Have you ever seen a split ring lock washer on anything yellow, except sheet metal?
A split ring lock washer is a spring made out of hardened steel. A fully compressed spring is unloaded. So how then is it to prevent a bolt from coming loose? The merchandizing says the sharp points on the washer are supposed to bite into the bottom of the bolt and the opposite mating surface. The problem with that piece of advertising is that for the ring to bite, the bolt has to come loose. That's why you see the scratch mark on the opposite side of the bolt head when you remove the bolt. Another question asked by the audience that year was about the hardness of the grade 8 bolt compared to the lock washer. The rep said the grade 8 bolt was harder that the washer. The other point that I've seen is broken lock washers where pieces have fallen out from under the bolt head. I throw them all away, even the ones that come on starter solenoids.
They might have loosening up.
Always talked like it was a steady problem and he's very particular so I'd tend to doubt it
Fellas sometimes get in trouble bolting attachments on like winches, grapples, blah, blah, because they fail to remove all the paint or rust from both mounting surfaces. The cap screws always come loose.
The only reason I disliked doing undercarriage - all that buffing and cleaning of paint and rust. The rest of the job I didn't actually mind.
I was instructed by an engineer, to solve a bolt breaking problem, by making a hardened spacer to use a longer bolt. Not a larger in dia bolt, simply a 1" dia. bolt added a 2" long hardened spacer. IIRC bolt went from 6" long to 8" long. Fixed the problem, as the bolt now stretched more when torqued, and never saw the loads.
Years ago I was working for a Kenworth dealer. The Kenworth service rep came to our shop to do an evening class on frame bolts as they had recently gone metric and were having problems. He got a couple of us to assemble two short pieces of frame rail and bolt them together with four new 16mm frame bolts with a strain gauge in between that was connected to readout that showed the tons of compression when I torqued the bolts to the factory recommended spec. Then he told me to loosen them and re-torque the four bolts again. The compression reading dropped by around twenty percent when the bolts were re-torqued. We were told to never reuse a frame bolt that was in a critical spot as they were one time use. A suspension bracket or torque rod or a cross-member always had to have the bolts replaced. It turned out that some of their bolt problems were a result of being supplied counterfeit bolts. Absolutely no torquing bolts with an impact wrench either.
I worked with a new to us, senior engineer that fixed our bolt problems....he specified Huck bolts. Now 1" huck bolts go off with a bang....I heard from the shop floor (having never used them before) that they sounded like a 30-06 when the shank snapped.
https://www.reddit.com/r/interestingasfuck/comments/zz5gyx/nut_innovation/?utm_name=iossmf Joe H
There are standard Nord Lock washers and they came out with an even higher strength version that is dished as well. They told me Nord Locks can be difficult to loosen. I used Nord Locks on my wheel adapters with short bolts because I didn't have much room on the backside for extra thread to protrude but looking at John Deere Ag equipment saw thick steel spacers at least an inch thick on bolt on wheels. It must be to get some extra stretch on the bolts. I maybe could have had spacers made because 40 1" Nord Locks cost $250.00cad. plus GST. The 5/8's were much more reasonable.
Lock washers are trash but in the small size and combined with a washer it "looks" right and in a non critical spot so I use them. Other places get loctite or bolt strech
Hardened steel flatwashers under bolt heads work good when properly torqued. That was the only method Cat used for many years with some special exemptions. Anyone remember the castellated(slotted) nuts with the special cotter pins used on con-rod nuts on some of the old cat engines?
I remember split lock washers that the ends were slightly thicker on opposing sides so they would bite into the bolt head and the metal below the washer. I always thought that was not a good idea as it could cause a crack to start at the bolt hole or damage the radius between the bolt shank and bolt head causing the bolt head to break off.
Definitely rings a bell. Not sure I've ever seen it in person.
Doing shovel work a guy gets good at putting lockwire on bolts. There's definitely an art to it.
Last day of the year, drinking coffee and talkin’ bout lock washers with my mechanic bro’s. I love it. You guys are awesome.
Skipping or doing a poor job of this critical step will bite you quick !!
I used to hook up new track chains to the forklift and make a few laps of the yard. Cut the prep time on that in half lol.
Anyone remember the castellated(slotted) nuts with the special cotter pins used on con-rod nuts on some of the old cat engines? Picked lots of pieces of cotterpins out of the oil pump screen on old Jag engines. Supposedly hitting the oil in the sump causes them to break. Joe H
Where's the discussion on 3 in 1 sewing machine oil?
Should we save the three in one discussion for this time next year? We still have a lot of washer stuff to talk about. For example, nobody has mentioned that hardened flat washers have a head side and a work piece side. We totally skipped that.
Yes and remember the stamped sheet metal lock nuts that went on the rod and main bearing studs after the nuts were torqued? I only ever saw one engine with them it was a 50's vintage Case gas engine in a Baker Hi Lift loader. One of the older guys I worked with was an engine machinist in the 50's and said they were common.
Oh My--1/4 flat for 5/16 bolts, 5/16 flat for 3/8 bolts and so on.
Oh My--1/4 flat for 5/16 bolts, 5/16 flat for 3/8 bolts and so on. The truth is out but I yet to find a proper fitting flat washer for a 1/4
Which side is WhICh? The hardened washers I use have a stamp on one side, just cause I'm ocd I always put that side towards the nut. Didn't know there was a right or wrong side. Did I fluke it the right way?
The crown goes towards the head.
Then there are rolled threads.
And thread classes, but we haven’t finished washers yet.
I have learned the hard way about re-using bolts on suspension components, especially Kenworth 8 bag sway bar bolts. When those break and the axle walks all over and you are laying under a loaded truck probably on a hill trying to get things back in position it tends to stick with you. It happened a couple times before I figured it out. New bolts properly torqued, no problems ever.
For close fitting washers, you want SAE washers, not the normal USS washers. Virtually all bolts have rolled threads. There are some specialty situations where threads will be ground, but they are uncommon. Cut threads may occasionally be found on specialty fasteners, but very rarely on modern bolts. Rolled threads are the strongest because of the cold forming. High strength bolts should have a chamfer on the hole to insure there isn't a square corner that will mark the radius under the head of the fastener and create a stress riser. If hardened washers are used, the washer should have a chamfer that will go against the bolt head.
And there we have it.
And in some rare cases the outside edge of the heavy washer has a radius from the stamping procedure that should go toward the spring to allow the spring to flex near the washer without causing a stress area which will lead to cracking and breaking. This would apply to some ag implements ie cultivator shanks at the upper end and maybe other similar situations
Any votes for tensiloc type washers.I have never found hard steel washers but these . They are not very thick but high tensile bolts dont dig in to them and they spread the clamping load of what you are bolting which can be important sometimes.
volvomad, CaseIH agricultural machinery use a lot of those washers. They are crowned, and called Belleville washers here in the USA. They are very good washers, but generally unavailable, even from the parts counter of the dealership. I have found unplated supplies, but not plated. The crown has the advantage of maintaining a little tension on the bolt, even after it has started to loosen.
Also NH uses them too. We usually use the term ‘belleville’ to refer more to the belleville springs but i guess the term may also be used to describe flat washers. They are available here from a few different sources
. If i remember right, we used to call them ‘pal’ nuts. Also used on old ford gas engines con rods such as the Y block series?
The ones I called Belleville are a conical spring washer.
I worked at Simplicity Engineering in school. Most machines had the decks held in with 3/4 Hucks. Larger ones used 1". Yea, you knew it when Grant touched the trigger on the 1" gun. Grant lived next door to me, built like a 100 year old oak stump. 5'4, 375lbs, massive fellow. He'd use the 3/4 gun by hand, the 1" got hung from an ovehead gantry.....lol. Ed
Aren't Belleville washers/springs what they use on track pins? I always thought they were smooth but maybe there are different types of them with the "teeth" on them. Click on find out more and there is a video for Nord Lock X series. Nord-Lock X-series Wedge-Locking Washers - Nord-Lock Group
Claas choppers are where I see these beville washers most on structural components, panels, reel tines and as slip clutch springs. I put them on all sorts but I dont have many sizes .