Why the HexSizer? (This is my document in progress)

HexSizer® Heavy Hex Gauge™ - Is a pocket tool that measures the Standard ASME 18.2.2 nut and bolt sizes. The sizes in this ASME Standard are referred to as Heavy Hex Sizes and are identified with a “2H” on the nut face. There is a Heavy Hex Nut Standard for Inches and for Metric.. The HexSizer® Heavy Hex Gauge™ generally comes in 2 sizes. A smaller size will fit in a wallet where the credit cards go. It measures nuts up to 4-5/8”. The larger size will measure up to a 6-1/8” nut and is usually stored on a Technicians badging lanyard. Standard nut sizes from 1-1/16" to 6-1/8".

Part of the task at hand is finding the correct and useful sizes to have on site:

What size are the hydraulic torque wrenches that you want on site and does your torque wrench supplier have on their shelf for rent? Or did you guess what size?
What are the nut sizes that I am working on in this power plant or refinery?

If II need a slugging wrench, hydraulic wrench, pneumatic torque Gun, 1” drive socket. 1-1/2” drive socket, 2-1/2” drive socket, or 3-1/2” drive socket what size do I need to order? I don’t want to order something that isn’t going to fit onto anything. Right?

HexSizer® Heavy Hex Gauge™ is a simple ruler that, from one flat, measures and identifies the ASME Standard Heavy Hex nut sizes and their corresponding ASME Standard stud sizes that are commonly used in Power Generation, Chemical Plants, and in the Oil & Gas industries.

It Measures from 1 flat rather than measuring across the flats.

You see, If a newbie technician asked how to find what wrench went to a certain nut, the answer would usually be, “Just measure across the nut flats, furthest from each other.” When writing this size, it is referenced with “A/F” which stands for “across the flats”.

However, the problem comes in when measuring installed nuts as the stud has a larger diameter than the nut flat. That makes it physically impossible to make an “Across the flats” measurement because now the stud gets in the way.

It is easy to understand how the larger a nut is in dimension, the further apart the A/F measurement will be. It is also true that for each flat of the hexagon, the larger the nut size, the larger each flat will become. The Heavy Hex Gauge measures from one flat or one side of the hex nut and then reflects that measurement as an “A/F” size. It's a very quick and accurate way to confirm a nut size in industrial environments.

The stud getting in the way is one dilemma. The difference between the actual size and the nominal size is another dilemma (A nominal size is a size designation that may not directly correspond to the actual physical dimensions of an object, particularly in construction and manufacturing.). If you have a 2” socket and a 2” nut, which one is actually two inches? They both can’t be.

In the ASME 18.2.2 Standard provides a minimum and maximum size. The maximum size is it’s nominal label ie. 2” nut is 2.0 A/F. As an example the ASME Standard allows that it can be undersized Min 1.938 where is nominal size is Max 2.00.

Maybe that is so you can quickly place and remove sockets. Maybe they know how the nuts will get beat up from dead blow mallets and slugging wrenches. That kind of treatment would be hard on a truly precision fit.

Anyway, Let’s say Joe-Bob the Bolting Technician measures a 2” A/F nut and it comes up 1.938”. But they are looking for 2.00” so they think, maybe it’s a Metric siize and get unsure about and loose a little confidence about this particular job.

Maybe, they tried to measure across the flats, the stud got in the way so they guessed at what the size should be by holding the ruler out from a distance and guessing where the tick marks would land.

Consider this:

The Standard size under 2” is 1-13/16” (1.812”)

The size over is 2-3/16” (2.188”)

which means it might be .188 or about 3/16” off either way by the nominal sizes.

That’s not a lot of room for guessing.

To compensate for not being so sure about the size, the Technician may use a ruler with finer graduations or use a caliper, with measures in 1/1000^th of an inch. Sure, either is very accurate but which one will answer Joe-Bob’s question, “What is the standard size wrench I would use on this application”.

Side Point – that is why the tick marks on the HexSizer Heavy Hex Gauge are only the standard sizes, so there are no other sizes to confuse you.

Measures installed nuts - The best tool for measuring installed nuts and stud bolts. No boards or cables to mess with. The bolt measure tool uses the bolt end and the nut measure tool from one flat.

So why do we need the nut so badly. The reason for needing the correct standard nut size is for the purpose of getting the correct wrench or impact socket selection. This serves two purposes.

One – it gives the technician confidence about the job in front of them. Just the “knowing” what job they are taking on gives confidence to the worker which in the end has a positive effect on the jobs final outcome.

Secondly – Industrial work is not generally executed by one person alone. There are always at least two so that if one person is immobilized for whatever reason the other person can run to get help. (the instruction for safety events when a man goes down is not to save the man, but to get help. I know…) Anyway, there are at least two craftsperson’s on the payroll.

That’s not all:

An Inspector is often there.

If the bolting work is in a confined space, there will be a “Hole-Watch” to document who goes in and when they exit.

Only a fraction of bolting work is done at ground level so there may be a need for scaffolding.

There will be a Scaffolding Build Team.

Somehow the bolting tools and other equipment needs to get on the level where the work is being done. This adds a Crane Rental & Crane Operator.

To get the crane mobilized will require a Crane Spotter (this person knows signals)

and rigging crew (only they can do rigging).

So, it’s not like there is one person on the payroll. There are many and they all need each other to work as a team. Looking at it this way, there is a lot that goes into the simple job of loosening some nut to open an inspection plate.

The plant, in general does not do their own construction. They do their own Engineering to specify work. Then those specifications go to an Industrial Contractor who actually does the work. The plant may contract another Engineering firm to oversee the work but at some point the work will end up with an Industrial Contractor that ends up fulfilling the actual execution of the work scope from the Plant Engineers.

Hypothetically, let’s say Field Tech, Joe-Bob brought the wrong size socket or wrench for this work at hand and now someone needs to go back to the shop to get the correct size. He goes back to the shop while all that crew we mentioned is now on hold.

Industrial Contractors work very hard and it is highly competitive to be awarded these contracts for work inside the plant or for the Engineering firm. For that reason, the Plant will hire several Industrial Contractor to keep on site so that if one drops the ball, there is another talented crew to replace them.

So, while Joe-Bob of off to the shop, there are competing Industrial Contractors who see the work has stopped and start asking the Plant Site Supervisor, “What’s going on here?”

Naturally, the plant wants to keep the work moving so if they can find a Contractor on-site with the necessary qualifications and tools already inside the plant, They will hand off the job to the competitor and not Joe-Bob may return with nothing to do. For that reason, the Contractor may have a Purchase Order from the Plant in hand. Simply to lock down and secure the work.

It’s worthy to mention that when the Plant does a unit shutdown, planned outage or turnaround, those are high budget events for everyone involved. The common way for Industrial Contractors to break into this work is to secure one small job and execute it flawlessly and sooner than planned. That is what earns the right for the Plant to trust the Contractor with more work. So that when the Contractor says to the Site Supervisor, “Hey we those tools here and can knock that out if you like.” The person in charge may well just say, “Sure!”

Another thing that is going on in the background are the Planners. Engineers may have pipeline tie-ins and valve insertions, but the Planners put together a timeline of events that make will make that happen. They use a software that plots time needed to execute the work to completion.

So near me is the Chevron El Segundo Refinery primarily produces transportation fuels: gasoline, jet fuel, and diesel. It also produces other products like fuel oils, petroleum coke, and LPG. The refinery has a capacity of 290,000 barrels of crude oil per day and is a major supplier of transportation fuels in Southern California.

Today gas is selling at Costco for $4.04 a gallon. So, money for this refinery is:

Per Year - $1,171,600 per day X 365 days in a year = $427,634,000 per year

Per day - $4.04 per gallon X 290,000 gallons a day = $1,171,600 per day

Per Hour - $1,171,600 a day / 24 hours = $48,816 an hour

Per Minute - $48,816 an hour / 60 minutes = $813.61 per minute

So Joe-Bob’s 30 minute trip to the shop is costing this refinery would cost the Plant:

$813.61 per minute X 30 minutes = $24,408.30 in uptime lost.

These are very loose estimates, but hopefully you can see how the Plant personnel who are connected to uptime or revenue would take a saving of 30 minutes or a trip back to the shop seriously.

There is a difference between sizing installed and uninstalled nuts.

The stud gets in the way of measuring across flats.

Job Titles that buy your product

Industries you serve best

Specific pain points you solve

How clients describe their problems

Pricing

Alternatives

Case Studies

Product Specific content

Problems that are specifically addressed by HexSizer FAQ GIFS Video Guides Troubleshooting Section Steps Examples

What is different or sepatares us from,

Save yourself from –

Doing job walks where you guess what wrench or socket sizes to use.

Being forced to trust old drawings for nut and bolt sizes.

Measuring across the flats of installed nuts where the stud is in your way.

Having to read tiny tick lines then guess which the right or standard size.

Having to read a caliper in 1/1000’s of an inch then guess which is the standard size.

Renting “One-of-Each size” just in case instead of renting only the bolting tools you need.

Stopping the job and the crew until the right size wrench or socket is onsite.

Leaving the job-site to making a trip back to the shop for the right size.

Loosing bolting work to your competitor while you off-site traveling back to the shop.

Save yourself from guessing nut and bolt sizes on job walks.

Or Measuring across the flats and the stud is in your way.

Or stopping the job and the crew because the bolting tools are the wrong size.

Or leaving the job-site to make a trip back to the shop.

Or being forced to trust old drawings.

Or having to read tiny tick lines then guess which one is the correct standard size.

Or having to read a caliper in 1/1000’s of an inch then guess which is the standard size

Or Renting “One-of-Each size” just in case instead of renting only the bolting tools you need.

Or loosing the bolting work to your competitor while you going back to the shop to get the right size tool.

Reasons

Selecting a wrench or socket for an installed nut is different than an uninstalled nut.
The stud gets in the way of an “across-flat” measurement.
Renting the wrench size above and below (tripling the cost) just in case we choose a wrong size.
Shipping a knack box of bolting equipment instead of just the sizes that is needed.
The trip back to the shop to get the correct size. Leaving the job and your crew.
Loosing bolting work to your competitor while you off-site traveling back to the shop.
A “2H” mark on the nut means it’s a standard size but my calipers measure a smaller size.
Saying, “It must be Metric or a custom build” when it’s not.
Saying, “I swear we need a 3” socket!”, when it was 2-15/16^th.
Guessing sizes on your job walks.
Being forced to trust old drawings for sizes.
Having to read tiny tick lines then guess which the right size is.
Having to read a caliper in 1/1000’s of an inch then guess which is the standard size.
Renting “One-of-Each size” just in case instead of renting only the bolting tools you need.
Stopping the job and the crew until the right size wrench or socket is onsite.

I’ve been in that spot where the plant can’t wait for the correct tools so they get the welders to burn the nuts off because the Time-Line can’t afford it. To do that, they have to:

Take welders off their current work scope and move them to this problem spot.
Hot permits have to be issued, approved and filed.
Fire-Watch on hand (they stay 30 minutes after as well).
Blind off the area
…now you are allowing an ignition source in a refinery! It’s done all the time but it’s a hazard.
HexSizer for companies serving Oil & Gas, Pipeline, Drilling, Power!

Just to recap:
The trip back to the shop.

Leaving the jobsite and your crew.

Stopping the job and the crew.

Loosing the work to your competitor who has tools onsite.

While you are off-site for the Planners and their timeline estimates.

Aug 14th 2025