

🔧 Nail every project with precision—your ultimate nut, bolt & screw sidekick!
This green Nut, Bolt & Screw Gauge by MarineBoltSupply is a durable, 1/4" thick plastic tool designed to measure standard and metric fasteners, including diameters, lengths, and thread pitches. It covers fractional sizes from #4 to 1" and metric sizes from 3mm to 22mm, with a compact 8.75" x 3.25" footprint. Featuring both coarse and fine thread pitch gauges, it streamlines fastener identification for DIYers and professionals alike, reducing errors and saving time on hardware runs.






| ASIN | B06X15YV6X |
| Batteries Included? | No |
| Batteries Required? | No |
| Best Sellers Rank | #27,697 in Industrial & Scientific ( See Top 100 in Industrial & Scientific ) #75 in Nut & Bolt Assortment Sets |
| Brand | Marine Bolt Supply |
| Color | Green |
| Customer Reviews | 4.6 4.6 out of 5 stars (1,811) |
| Cutting Diameter | 1 Inches |
| Date First Available | February 10, 2017 |
| Fastener Type | Nuts |
| Finish | Unfinished |
| Head Style | Hex |
| Head Type | Hex |
| Is Discontinued By Manufacturer | No |
| Item Diameter | 1 Inches |
| Item Hardness | thick hard |
| Item Package Quantity | 1 |
| Item Weight | 2.08 ounces |
| Item model number | 1-NBG |
| Manufacturer | CMC Industrial Supply |
| Manufacturer Grade | Grade 2 |
| Material | Plastic |
| Measurement System | Inch, Metric, inch_and_metric |
| Number of Pieces | 1 |
| Part Number | 1-NBG |
| Shape | Rectangular |
| Size | 1/2-13 UNC |
| Thread Class | 3B |
| Thread Style | Right Hand |
| Thread Type | Unc |
K**R
Great product and price for DIY engineers and mechanics
I do a lot of DIY engineering and mechanical projects and I waste a ton of time hunting the right size nut, screw, bolt, etc. This simple, well-made sizing tool is one of the absolute best aids I have ever bought. I even take it with me to Home Depot and Lowes to make sure I'm getting the correct product size...no returns or multiple trips for mis-matched sizes. Thank you to whomever created and sells this product.
R**U
Don't let the 'meh' reviews deceive you.
I hesitated to buy this thing, because while the overall review score is good, the 'Top Reviews' paint a different picture. I'm glad I bought it anyway. Wanted to respond to some of the issues other reviewers had: "Very small and there aren't any threads in the holes or the pegs that are supposed to measure nuts" If 7 inches is very small, then a lot of dudes are in trouble, myself included. It's true, the holes and pegs are not threaded. It's made of plastic, that would work maybe half a dozen times before they deformed and were no longer accurate. Instead, there is a thread gauge on the back for bolts/screws, and the pegs for nuts define thread pitch by whether or not they fit completely over it. If they can't clear the 'shoulder' of the peg halfway down, they're coarse pitch. If they can, they're fine pitch. Then just look at the conversion table printed right there on the front of the thing and boom you got your thread count. Unless you're working on NASA equipment, this will solve most any dilemma you're having with your nuts (lol) "Has no way to check the thread pitch of nuts... only their inner bore diameter." The info is right there on the unit...fit the nut to the peg, note and size and if it's coarse or fine pitch, and look at the conversion table. Metric and standard. "I need one that will define what sort of thread a given bolt happens to have, e.g., how many threads per inch? " On the back side, there's a metric and US thread pitch gauges. I'm more used to using the ones at the hardware store that are set up where you actually thread it into a hole, but this tool is easier in my opinion. The way to use it is to press the bolt on top of each gauge and try giving it a little nudge to the lateral side. If it's not a match, the bolt will kinda jitter off the plastic. When you get a match, it will 'bite' the threads and won't budge. You'll know it when you hit the sweet spot, trust me. It's easier this way because once at the hardware store I accidentally used a US bolt on the metric hole and it got locked up in there. Had to flag down an employee and have him get it out using tools. Anyway, I think this gauge is pretty useful for the DIY crowd and the price is right for most of us. It's pretty bad when misleading reviews get upvotes. This one will probably get downvoted, but I hope it helps at least one person who kept scrolling down.
K**R
Perfect size
This is a great product and perfect size.
A**.
Does an okay job at *estimating* sizes. NOT a measuring tool!
Short and sweet overview: Decent product, plastic. Has a great layout that makes measuring easy. However the thread checker is hard to use. Bolt sizing is an estimate! I had a bunch of screws/bolts to measure and some were all very close in size. I ended up buying a metal threaded one that I could screw into and actually verify it's the size I'm looking for. If you're looking for a rough estimate on a screw size, this is what it is for. Otherwise, get a metal threaded one. Here's a more detailed review of the things that stuck out to me: The Good: 1. Works well for what it does. Has both imperial and metric measurements but can be hard to tell the minute differences between the two sizes on similarly sized screws. The Bad/Improvements: 1. Thread checker is meh. I was trying to use this alot because its really the only way to tell if an unknown screw is metric or imperial. Unfortunately the limitations of the design mean that its really hard to accurately gauge thread pitch on screws. 2. Screw size is an estimate! If you have a bunch of unknown screws like I did, this makes it easy to generally classify size. Can you tell between an M8 screw and a 5/16th? There's no way to accurately tell. Can you tell if it is an M8 OR a 5/16th's? Yes defiantly.
M**.
No more cross threads.
Must have if you hate cross threading bolts.
G**N
Good value, great for your tool box
This is very nice to have when you are trying to figure out what nut or bolt you have. My only complaint is I wish it was in metal rather than plastic, but for the price, this is a great tool.
R**T
good tool. could use minor improvement.
needed something CHEAP to measure some bolts and threads. Searched quite a bit for different options, this one had the thread count embedded, so decided on this one. I like the product except the print on the back for the threads is NOT readable. I tried to use a sharpie to make it stand out, not great but gets the job done. Would be better if it was white lettering vs. natural plastic for the thread count (like on the front). Photo 1 is the front, photo 2 is the back.
K**A
Garage necessity
I bought these for Christmas gifts. Everyone who received them thought they were a great gift. Loved that they were easy and portable.
M**Z
En mi taller de casa lo uso para identificar con facilidad tornillos
S**M
This gage was easy to use and I am able to find the size of the bolts easily.
A**X
llegó con la medida para la rosca de 5/16" quebrada
K**L
I like the simplicity of this product. I use it for sizing nuts and bolts that require replacement.
M**N
Excellent tool for measuring and confirming threaded bolt dimensions
Trustpilot
5 days ago
2 days ago