Help with 411 in the world of wrenches, sockets, bolts, etc.


Old 12-15-12, 02:35 PM
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Help with 411 in the world of wrenches, sockets, bolts, etc.

So today I was roaming Lowes looking at all the types of wrenches. I have to tighten 1/2 inch hex bolt and nut. I was confused for the longest time because I thought logically, you need to look for 1/2 inch wrenches or sockets for those ratchet wrenches. I figured out the size wrench or socket I needed was 3/4. For my educational purposes, I asked an employee to explain this and to make matters worse, he told me the numbers should match, "If you want to tighten 1/2 bolts, you need 1/2 wrenches." Then he even took me to the aisles and tried to fit some wrenches to the bolts, and he himself had a look of confusion. I just chalked it up as him being a newbie like me. So here are my questions...

1. Is the labeling wrong at my local Lowes? I think I already know the answer to this. It is not wrong, I'm a newbie.

2. Okay, so if it's not wrong, then is there a universal calculation to figuring out wrench sizes for the different nuts and bolts I will encounter in the future? In my situation, it was adding 1/2 inch. Is adding half an inch the universal math?

3. All my life, the way I tighten nuts and bolts is with two wrenches. One is to hold the bolt, while the other is to do the turning on the nut. But there must be some something for this that would eliminate the need for a 2nd wrench, right? Is there anything that we can put on the bolt and not have to hold it?

Thank you for your time!
Old 12-15-12, 02:43 PM
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I'm not entirely sure I understand your question
The wrench size is dictated by the size of the bolt's head or nut. Metric nuts/bolts use wrenches or sockets that increase by the metric sizes, same goes for SAE.
Sometimes a lock washer will keep the nut from spinning once it gets partly tight but normally you always use a wrench [or socket] on each side.
Old 12-15-12, 02:49 PM
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The size of a bolt is expressed by it's diameter not its head size.
A 1/2 bolt fits in a 1/2 hole and normally uses a 5/8" wrench.
A 3/8 bolt fits in a 3/8 hole and normally uses a 9/16" wrench

You can put a star washer between the nut and the metal and it will hold the nut from spinning.
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Old 12-15-12, 02:58 PM
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Okay, thanks guys!

BTW, today I also saw something called "stop nuts" right next to the "Lock nuts." What's the difference?
Old 12-15-12, 03:01 PM
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Well...1/2" bolt will have a larger head and the nut will probably be one size larger than that. Even that can vary depending on the bolt and nut. 1/2" designates the size of the bolt shank...not the head or nut.

That's why you buy things in sets. I'm no Pro, but I have at least 4 sets of combo wrenches (2 SAE, 2 misc individual pieces), same for sockets only more so.
Old 12-17-12, 07:19 AM
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Hex Nuts and Bolt Heads

The wrench or socket size is determined by the measurement between parallel sides.

I measured a 1/4" nut (fits a 1/4 x 20 tpi bolt) and the wrench size needed is 7/16" (distance between parallel sides of the nut).
Old 12-30-12, 03:27 PM
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no real "formula", just use them enough and it comes natural, 3/8 bolts 9/16 wrench, 1/2 bolts 3/4 wrench 5/8 bolts 15/16 wrench, 7/8 bolts 1 1/4 wrench, 1" bolts 1 1/2 wrench...

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