Fastener Identification Question

[kc27]

In the photo below, is the dark colored fastener considered a screw because of the tapered end, and the light colored fastener a bolt? The light colored fastener is a replacement from Ace Hardware. Even though the threads are the same, it will not thread into the female threads on the Briggs & Stratton small engine for which I bought it. Should I have searched the bins at Ace for screws, not bolts?

 

[Jim greengo]

Are you sure the threads are same?
Looks differant to me inthe picture anyway.

 

[firebirdparts]

The word I use is "body bolts" typically used with sheet metal speed nuts. There are two flavors. Some have a pointy end that is threaded and the other is as you see here, piloted. They are used to hold car fenders and hood on, basically.

You can buy them in the "specialty" bins. Using google "body bolts" both styles pop right up and available amazon, auto parts stores,

 

[JSGAuto]

The pitch may be the same, but the major looks larger for the one on the right. What are the actual measurements?

 

[Al G]

Take it to Ace and ask for help finding a match. If they have it they'll find it.

 

[Cougar]

Could it be metric.
If you hold them together do the threads mesh.

 

[Zeke]

^^This

 

[BillK]

Post a picture of the heads on both of them. Home Depot has a thread checker hanging in the hardware section that you can use to check thread sizes. Or you can go to Ace and find a nut that fits your bolt and then find a new bolt that is the same size ?

The dark colored fastener is probably a better grade than the light one but the head markings will tell for sure.

Also agree with Jim, the one on the right looks larger diameter than the one on the left.

 

[BillK]

Could it be metric.
If you hold them together do the threads mesh.

There are a couple of metric sizes that are very very very close to sae sizes and hard to tell even holding them together.

 

[kbs2244]

looks to me like the same thread count but a different outside dia.
look in the bolt bins

 

[whateg01]

They appear to be the same pitch to me, but different thread form. If the one on the left is indeed self tapping it doesn't appear to cut the threads. It looks like it just forms a bit of a thread in something. The rolled form doesn't look at deep as the one on the right. If you mic it, you'll probably find that the major diameter is about a half mm smaller than nominal which is why the bolt on the right isn't going in. After confirming the thread pitch is the same, I would run a tap in the hole to open it up to the correct dimension then use the bolt on the right.

 

[egdede]

Firebirdparts gave you the answer: body bolts

Amazon.com : auto body bolts

 

[PCustoms]

The point should not matter.

Those bolt threads are not the same.

 

[Zeus36]

In the photo below, is the dark colored fastener considered a screw because of the tapered end, and the light colored fastener a bolt? The light colored fastener is a replacement from Ace Hardware. Even though the threads are the same, it will not thread into the female threads on the Briggs & Stratton small engine for which I bought it. Should I have searched the bins at Ace for screws, not bolts?

From the web:

"...Bolts are defined as headed fasteners having external threads that meet an exacting, uniform thread specification such that they can accept a non-tapered nut. Screws are defined as headed, externally-threaded fasteners that do not mate with a non-tapered nut and are instead threaded into the material they will hold..."

AND

"...Briggs & Stratton Metric engines require metric fasteners and drivers for the assembly and disassembly of engine components. Unless specified, the crankshaft features and crankcase cover mounting flange remain as SAE threads..."

 

[Zeke]

And those bolts look like the shroud bolts, so not the crankcase cover. Good to know about the SAE.

 

[kc27]

An Ace Associate used my original (the black fastener) to provide the spare for me. Three of these fasteners are used to attach the air cleaner base to a carburetor on a Briggs & Stratton 6-hp, 4-cycle engine. No nuts are involved. Two screw into the casting on the carburetor facing and the third goes on a stud to the side of the carburetor. From what firebirdparts said, I bought a generic fastener instead of the task specific made automotive type fastener.

 

[whateg01]

Two screw into the casting on the carburetor facing and the third goes on a stud to the side of the carburetor.

A stud is a threaded male fastener that sticks out of a surface. It looks like the threaded part of a bolt.

 

[jkuro]

Its called a machine screw.

 

[BillK]

An Ace Associate used my original (the black fastener) to provide the spare for me. Three of these fasteners are used to attach the air cleaner base to a carburetor on a Briggs & Stratton 6-hp, 4-cycle engine. No nuts are involved. Two screw into the casting on the carburetor facing and the third goes on a stud to the side of the carburetor. From what firebirdparts said, I bought a generic fastener instead of the task specific made automotive type fastener.

The one on the right is metric. I dont recognize the head marking on the Briggs bolt but I bet it is SAE. What size wrench or socket fits it ? Probably 1/4 x 20 thread

 

[The Cobbler]

hold the threads together & see if they mesh perfectly. if not, you have the wrong pitch. if they do match it may just be a case of poor tolerances on the Briggs , and a tap will bring it in to spec.

 

[BillK]

I am pretty sure that Briggs has all of the parts diagrams and lists on their web site. You should be able to look it up and see exactly what it is.

 

[PoorUB]

An Ace Associate used my original (the black fastener) to provide the spare for me. Three of these fasteners are used to attach the air cleaner base to a carburetor on a Briggs & Stratton 6-hp, 4-cycle engine. No nuts are involved. Two screw into the casting on the carburetor facing and the third goes on a stud to the side of the carburetor. From what firebirdparts said, I bought a generic fastener instead of the task specific made automotive type fastener.

Many screws in production are self tapping, or thread forming. The black screw is one of them. You might find a screw of similar pitch and diameter and it might not thread into the hole. For those times, when I can not get the OEM hardware I will run a thread tap into the hole to fit the replacement screw.

Also, for those saying to buy an OEM replacement, it might take weeks to get one as most parts suppliers don't carry every little odd nut and bolt from the OEM. I was a B&S dealer for 5 years and I didn't stock any OEM hardware. You can order online but you might end up with the same issue, or $15 freight for thee 6 MM screws.

 

[BillK]

For those times, when I can not get the OEM hardware I will run a thread tap into the hole to fit the replacement screw.

Sorry guys, I simply cannot comprehend doing this. Get the correct fastener size.

 

[PoorUB]

Sorry guys, I simply cannot comprehend doing this. Get the correct fastener size.

So, you have a machine you need right now and the OEM fastener is not readily available, so you wait instead of doing a reasonable repair?

I am not talking some hack repair. I am talking about replacing a 6 MM thread forming screw with a regular 6 MM screw of the same pitch. I don't see an issue. Plus we are talking about an air cleaner, not some critical fastener.

A connecting rod bolt, no way, get the OEM or some reasonable aftermarket hardware designed for the application.

Now if you are taking out the 6 MM screw and ramming in a 3/8" UNC bolt I can understand your concern.

 

[charbar]

Maybe its just my eyes but the threads on the black bolt look fubared. Are you sure the threads on your engine are ok?

 

[kc27]

A stud is a threaded male fastener that sticks out of a surface. It looks like the threaded part of a bolt.

Thanks for the clarification. The piece I described as a stud is a bracket with a threaded hole in it for the fastener.

I am pretty sure that Briggs has all of the parts diagrams and lists on their web site. You should be able to look it up and see exactly what it is.

They do. I wish they included the specifications of the fasteners. The parts catalog states "Part 94873, Screw -Hex" and that is all.

The three fasteners with shipping is about $30 on the low end from the online parts sources I checked. I was trying to expedite a repair and save some money by going to Ace. If it was a vehicle, I would just go to the you-pull-it recycling yard and be done already.

 

[mikedodge]

I've had the situation before that even with threads being the same the type of bolt on the left wasn't self tapping but the end helped guide the bolt into the hole to start it. Otherwise while you could get a normal bolt to start you had to be right at the hole in the perfect spot or it was a pita to get it started.

 

[PCustoms]

Thanks for the clarification. The piece I described as a stud is a bracket with a threaded hole in it for the fastener.

They do. I wish they included the specifications of the fasteners. The parts catalog states "Part 94873, Screw -Hex" and that is all.

The three fasteners with shipping is about $30 on the low end from the online parts sources I checked. I was trying to expedite a repair and save some money by going to Ace. If it was a vehicle, I would just go to the you-pull-it recycling yard and be done already.

You've got the wrong screw. I can't quite tell from the pic if it's pitch or diameter that is off, but it's wrong plain and simple.

Forget all the self tap etc nonsense, go find a thread gage and try it yourself. If you can't find the right screw for some reason, the pn you posted can be had for $10 with free shipping from several sources. It looks like it has been superseded by an even cheaper screw, for $20 you could have a set of 3.

Why are you swapping them all out?

 

[jonesg]

a bigger impact will solve that.

 

[whateg01]

You've got the wrong screw. I can't quite tell from the pic if it's pitch or diameter that is off, but it's wrong plain and simple.

Forget all the self tap etc nonsense, go find a thread gage and try it yourself. If you can't find the right screw for some reason, the pn you posted can be had for $10 with free shipping from several sources. It looks like it has been superseded by an even cheaper screw, for $20 you could have a set of 3.

Why are you swapping them all out?

You're paying $10 for 25 cent part that holds an air filter on??? Jfc. It's no wonder places charge what they do for stuff. There's somebody that will pay it.

 

[kc27]

The fastener I bought from Ace was a m5-.80. This afternoon I purchased metric and SAE screw pitch gauges. I used a soldering stand that has a magnifying glass to help out my eyes. Both fasteners look to be .8 pitch. The Ace fastener is 4.7 mm diameter, the OEM fastener is 4.4 mm diameter.

The word I use is "body bolts"

Ace Hardware in my area carries six body bolts that do resemble the OEM bolt, but none in the size I needed.

Thanks everyone for the help. I can set this project aside and wait to find used OEM screws. I am replacing a missing air cleaner box, and should have purchased a used OEM assembly that included the fasteners.

Now I understand why people who have the storage space warehouse dead or no longer needed small engines. The parts are right at hand and the price is right.

 

[CJDave]

In the photo below, is the dark colored fastener considered a screw because of the tapered end, and the light colored fastener a bolt? The light colored fastener is a replacement from Ace Hardware. Even though the threads are the same, it will not thread into the female threads on the Briggs & Stratton small engine for which I bought it. Should I have searched the bins at Ace for screws, not bolts?

A company named Auveco has all kinds of automotive nuts, bolts, screws and clips. CJDave.