home improvement : the nuts and bolts of fasteners
Well, on the one hand, program your video recorder, cover your eyes and wear gloves.
You may have experienced this before: you walk into the hardware store and head straight to the bolts of those small boxes, hoping that you can find what you want before the salesperson \"helps\" you with a long list of questions.
\"Do you want carriage bolts, machine bolts or furnace bolts?
Can I show you something about a stainless steel machine screw? What size?
Thin line or thick line?
Do you need a grade of special hardening?
\"Hopefully you bring an example of what you want.
Otherwise, you may get lost after the first round of questions.
However, arm yourself with some basic facts and you can be in charge the next time you go shopping in Bolt.
Let\'s take a look at the basics.
Dimensions: bolts are sized in the order of diameter, thread and length.
In most cases, the diameter and length are listed in inches, and the threads are listed in inches. Thus a one-fourth-
Bolts in inch diameter, 20 threads per inch, 2 inch long, will be listed as 1-
X 20x 2 inch or quarterly/20x2 inch for the fourth quarter.
Sometimes threads are listed as UNF (fine)or UNC (coarse)
Not every inch.
Just a small change to make things interesting.
Why are there different types of threads?
Thin threads are stronger than thick threaded bolts and can be screwed tighter.
They are also better on smaller bolts.
On the other hand, the thick line is harder.
They will perform better at heights.
Wear conditions, or when you may have to remove or replace the bolts frequently.
They also resist cross threads better than thin threads.
If you have to buy a bolt to install a specific nut, take the nut to the store and make sure you can screw it to the bolt you bought.
Thread it all the way.
Sometimes, even if the nut does not match the thread of the bolt, it turns a circle or two.
More about size: Surprise!
Not all bolts are in inches in diameter.
Machine screws are sized according to quantity.
The smallest size is not available. 6 (one-eighth inch);
The biggest thing is No. 14 (5/16 inch).
Don\'t forget the indicators.
For example, if you work on imported cars or bicycles, you may encounter these problems.
The metric hardware is sized according to a different set of standards, and it does not swap with other hardware.
You even need a set of metric wrenches to install the metric head.
When it comes to the head, this opens up a new set of variables.
Some bolts have square heads and some have hexagonal heads.
Which is better?
If you have a set of socket or box wrenches, you will prefer the hex wrench.
Your wrenches will fit them and you can work faster in closer places.
If you work mainly with an adjustable wrench, you may prefer the square head.
A sloppy adjustable wrench can slide and bypass a hexagonal head for a short period of time, but there should be no problem catching a square head.
Enough size and head.
Let\'s take a look at some of the basic types of bolts.
Furnace bolts: these are slotted screws
Type the head, which can be round or flat like the head in the upper left corner of the sketch.
They have course lines and often Square nuts.
Diameter from 1-
The length is about three-
The furnace bolts are quite rough, made of carbon steel and roughly finished.
They can be used regardless of appearance, rust resistance and super strength.
Keep in mind that since they are tightened with a screwdriver, you can\'t usually tighten them like a hex or squarehead bolts.
Machine screws: these also have slotted heads.
However, they are finer than steel and easier to get in metal.
In the Ocean shop, you can find that they are plated in solid brass, bronze or even stainless steel.
Machine screws with hextype nuts.
You can use them for fine to medium work no matter you want a screwtype head.
Where is it possible?
Any place where there is not enough space to use a wrench, or where a prominent hexagonal head may be out of the way or out of the way.
You can use the apartment
For example, fix the hinge with a countersunk screw or other hardware with a countersunk hole.
Machine bolts: these, also known as Cup screws, are classic working bolts.
They are in inches and almost always have hexagonal heads.
If you need high strength and wear resistance, the machine bolts are made with special grades, which are coded by the marks on the head.
Ordinary steel bolts are not marked at all.
High-strength bolts will have radiation spokes
Like the mark, the more \"spokes\" The stronger the bolt is.
For example, the bolts at the bottom of the sketch have three marks, which are the fifth grade. High-
Strength bolts are not necessary for most jobs, but you may need them for certain automotive applications.
If the bolt you are replacing needs to be marked, make sure the bolt you purchased is also marked.
Transport bolts: These bolts are used on woodto-
The connection of wood or metal to wood.
The carriage bolt has a round, unopened head with a square shoulder underneath it (
Like the bolts in the top right corner of the sketch).
When you tighten the nut on the transport Bolt, the square shoulder under the head sinks into the wood and grabs to prevent the bolt from turning.
This allows you to install bolts with a wrench, which also makes the bolts good for secure applications such as fastening hinges, locks, latches, etc.
Since the head is smooth and there is no slot, you cannot remove the bolt unless you can reach the nut.
The smooth head also makes it a good choice to transport bolts where the protruding hex or square head may be in danger.
Outdoor furniture and amusement equipment are two good examples of this kind of work.