Best Bolt Gauges of 2025

Brian Howie Avatar
Brian Howie
Last Updated: Jan 9, 2025

* We independently evaluate all recommended products and services. If you click on links we provide, we may receive compensation.

Bolt gauges are essential tools for anyone working with bolts and nuts. These gauges are designed to accurately measure the size and length of bolts, as well as their thread pitch and diameter. They come in different sizes and shapes to fit various bolt sizes and can be used for both metric and imperial measurements. Bolt gauges are made of high-quality materials and are built to withstand harsh working conditions. They are easy to use and can help save time and money by preventing errors and ensuring the right bolts are used for each job.

At a Glance: Our Top Picks

AltitudeCraft Thread Checker Cover #TOP 1
AltitudeCraft Thread Checker
ftb score rating icon 9.8
Stainlesstown Nut Bolt Thread Gauge Cover #TOP 2
Stainlesstown Nut Bolt Thread Gauge
ftb score rating icon 9.7
Screw Bolt Nut Thread Gauge by BoltsandNuts.com Cover #TOP 3
Screw Bolt Nut Thread Gauge by BoltsandNuts.com
ftb score rating icon 9.5

Top 10 Bolt Gauges

AltitudeCraft Thread Checker

AltitudeCraft
AC072
One Size
AltitudeCraft Thread Checker Cover
AltitudeCraft Thread Checker, Nut and Bolt Thread Checker, Bolt Size and Thread Gauge, Bolt and Nut Identifier Gauge, Bolt Gauge

AltitudeCraft Thread Gauge is a masterfully crafted tool made with durable SUS304 material. It features a wide-ranging size detection that instantly identifies 28 distinct sizes, including Metric thread sizes from M4 x 0.7 to M14 x 2.0, and Imperial threads from #6 – 32 Fine to 1/2 – 20 Fine. The laser-etched double scale provides quick and accurate identification of various thread sizes in inches and centimeters. The strong and portable design, made of lightweight 6061 aluminum, allows you to take it to different workplaces effortlessly. Mountable on a wall or toolbox, this convenient and essential tool is perfect for professionals and DIY buffs alike.

What We Like
Durable SUS304 Material
Wide-ranging size detection
Laser-etched double scale
#TOP 2

Stainlesstown Nut Bolt Thread Gauge

Stainlesstown Nut Bolt Thread Gauge Cover
Stainlesstown Nut Bolt Thread Gauge (Red)

The Stainlesstown Nut Bolt Thread Gauge is a versatile tool that allows you to measure the diameter, thread pitch, and length of nuts, bolts, and screws. With the ability to measure both fractional and metric bolts, this gauge covers a wide range of sizes, from #4 to 1" and 3mm to 22mm. Made of durable 1/4" thick hard plastic, this gauge is built to last. Its compact size, measuring 1/4" thick x 8-3/4" long x 3-3/8 wide, makes it easy to carry and store. Whether you are a DIY enthusiast or a professional, the Stainlesstown Nut Bolt Thread Gauge is a must-have tool that will save you time and effort in accurately determining the dimensions of your fasteners.

What We Like
Versatile Measurement
Wide Range of Sizes
Durable Construction
#TOP 3

Screw Bolt Nut Thread Gauge by BoltsandNuts.com

Gauges-BoltNutGauge-Red
Screw Bolt Nut Thread Gauge by BoltsandNuts.com Cover
Screw Bolt Nut Thread Measure Gauge Size Checker (Inch Standard & Metric)

The Thread Gauge by BoltsandNuts is a versatile tool designed for both inch and metric measurements, making it ideal for various projects. You can easily measure bolt sizes ranging from #4 to 1 inch and lengths up to 7 inches. For metric users, it accommodates sizes from 3mm to 22mm. The durable construction of this gauge, made from 1/4-inch thick hard plastic, ensures longevity and reliability. Its compact size of 8-3/4 inches long and 3-3/8 inches wide makes it easy to store and handle, providing you with a convenient solution for all your threading needs.

What We Like
Inch and metric measurements
Durable hard plastic construction
Compact and easy to store
Measures a wide range of sizes

JoblikeBrez Thread Checker

JoblikeBrez
Thread Checker
JoblikeBrez Thread Checker Cover
JoblikeBrez Thread Checker, 30 Nut and Bolt Thread Checker, Bolt Size and Thread Gauge 15 Standard & 15 Metric, Thread Pitch Gauge, Wall-Mountable Bolt Thread Identifier Gauge with Inch & CM Ruler

JoblikeBrez Thread Gauge is a precision tool that simplifies identifying 30 nut and bolt thread sizes, adhering to ANSI standards for accurate sizing. By matching your hardware with the corresponding slots, you can effortlessly determine the size and pitch, eliminating guesswork. Crafted from durable aluminum, it includes drill gauges for added functionality. With its intuitive design and easy-to-read markings, even beginners can use it with ease. The versatile mounting options make it convenient for both hanging on a wall and placing on any surface while working.

What We Like
Precision Sizing
30 Nut & Bolt Sizes
Easy to Use
#TOP 5

Manalete Thread Checker

Manalete
30 Nut and Bolt Thread Checker
Manalete Thread Checker Cover
Manalete Thread Checker, 30 Nut and Bolt Thread Checker, Bolt Size and Thread Gauge, Bolt and Nut Identifier Gauge with 15 Standard & 15 Metric &19 Drill Bit Gauge,Screw Size Gauge

Manalete Bolt Thread Gauge is an excellent identification tool that quickly identifies 28 different sizes of bolts and nuts in both inch SAE and metric threads. The durable thread checker is made of high-quality materials ensuring maximum thread strength and precision accuracy. The easy-to-read markings with white lettering on a red background make identification quick and accurate. Its convenient design with pre-drilled mounting holes allows for easy storage and portability, making it a must-have tool for professionals and DIY enthusiasts.

What We Like
Durable materials
Easy identification
Convenient design
#TOP 6

Xxzhiho Nut and Bolt Thread Checker

Xxzhiho
Black, Silver
Xxzhiho Nut and Bolt Thread Checker Cover
Nut and Bolt Thread Checker (Inch & Metric) - 26 Male/Female Thread Identifier Gauges - 14 Inch & 12 Metric Sizes (26 Gauges-14 Inch & 12 Metric)

Xzhizho Thread Checker is a versatile tool with several user-friendly features. The black oxide coating for metric sizes and zinc plating for inch sizes make identifying thread sizes a breeze. The comprehensive range of 26 male/female gauges, both inch and metric, are conveniently assembled on a wire loop for portability. The sturdy stainless steel construction ensures durability for professionals and DIY enthusiasts alike.

What We Like
Wide size range
Portable design
Durable stainless steel
#TOP 7

Xxzhiho 44-Piece Thread Gauge Set

Xxzhiho
One Size
Xxzhiho 44-Piece Thread Gauge Set Cover
44 Male/Female Bolt Size and Thread Gauge,Nut and Bolt Thread Checker 23 Inch & 21 Metric Sizes,Nut and Bolt Size Gauge,Individually Assembled Thread Gauge(44pcs Alloy Red&Blue)

The Xxzhiho Thread Gauge Set is an essential tool for anyone working with nuts and bolts. Its sturdy aluminum alloy construction ensures durability, so you can rely on it for years. With 21 metric sizes and 23 inch sizes, you can easily find the right fit for your projects. The fast size finder feature allows you to quickly measure bolt sizes and thread gauges, saving you time and reducing mistakes. Plus, the organized foam storage keeps everything in place, making it convenient to carry and use whenever needed.

What We Like
Durable aluminum alloy construction
Comprehensive size range
Quick and accurate measurements
Organized storage for easy access
#TOP 8

NAMOKA Thread Checker Gauge

NAMOKA
Tread Checker
NAMOKA Thread Checker Gauge Cover
NAMOKA Thread Checker, Nut and Bolt Thread Checker, Thread Checker Standard and Metric, Identify 16 SAE & 15 Metric Sizes, Bolt Size Finder, Durable Aluminum Alloy & Stainless Steel Thread Gauge

The NAMOKA Thread Checker is a versatile tool that helps you accurately identify both metric and standard threads. With its wide compatibility of 31 sizes, you can quickly find the right bolt for any project, whether it's for DIY repairs or professional use. The dual-panel design allows for easy separation of small and large threads, making identification faster and more efficient. Its durable construction from stainless steel ensures it withstands tough environments, while the compact design saves space in your toolbox, making it a practical choice for any mechanic or DIY enthusiast.

What We Like
Wide compatibility with sizes
Durable stainless steel construction
Efficient dual-panel design
Compact and portable
Convenient for on-site repairs

Giwaelro Nut and Bolt Thread Checker

Giwaelro
Giwaelro Nut and Bolt Thread Checker Cover
Giwaelro Nut and Bolt Thread Checker - 26 PCS Nut and Bolt Gauges Individually Housed in Case (14 Inch & 12 Metric) Specially Suitable for Size Check on Tricky and Narrow Area

The Giwaelro Thread Checker is designed to enhance your threading tasks with its user-friendly features. Each gauge is stored separately in a foam case, making it easy for you to grab the one you need without fuss. The dual-sided laser-etched sizes help you quickly identify both metric and standard measurements, saving you time. Additionally, the gauges offer three clear ways to read sizes, allowing for effortless identification. With this tool, you can efficiently check and replace nuts and bolts without the hassle of running to the hardware store, streamlining your home or garage projects.

What We Like
Easy size identification
Quick access to gauges
User-friendly design
Time-saving tool
#TOP 10

Caikvwen Thread Checker 28 Sizes

Caikvwen
Liangui00001
Caikvwen Thread Checker 28 Sizes Cover
Caikvwen Thread Checker, Professional Nut and Bolt Thread Checker with 28 Sizes, Premium14 Metric & 14 Standard Identibolt, Accurate Thread Gauge with Centimeters and Inches Scales on Both Sides

The Caikvwen Thread Checker is a versatile tool designed for identifying a wide range of bolt and nut sizes. Crafted from high-quality SUS304, this thread checker ensures durability and precision. You can easily measure both metric and imperial threads, with 28 different sizes available, making it practical for various applications. The laser-etched scales in inches and centimeters prevent fading, allowing for quick and accurate measurements. Its lightweight aluminum construction also makes it portable and easy to store, as it features a convenient hanging hole. This tool is perfect for professionals and DIY enthusiasts alike.

What We Like
Durable SUS304 construction
Identifies 28 sizes
Laser-etched, fade-resistant scales
Lightweight and portable
Easy to store
Buying Guide Image

Guidelines for Choosing the Right Bolt Gauges

What are Bolt Gauges?

Bolt gauges are an essential tool for any mechanic, engineer, or anyone else who needs to measure the diameter and length of bolts. They are easy to use and can quickly and accurately measure bolts of various sizes and lengths. They are also essential in ensuring that the bolts are properly sized and can fit into the required openings.

Types of Bolt Gauges

There are two main types of bolt gauges: digital and analog. Digital bolt gauges are more precise than analog gauges and can be used to measure a variety of sizes and lengths. They typically have a digital display that allows you to easily read the measurements. Analog bolt gauges are generally less accurate than digital gauges and are mainly used for measuring the length of bolts.

How to Choose the Right Bolt Gauge

When it comes to choosing the right bolt gauge, there are a few things to consider. First, you need to identify the type of bolts you will be measuring. This will help you determine whether you need a digital or analog gauge. If the bolts are standard sizes, an analog gauge will be sufficient. However, if they are non-standard sizes, a digital gauge is likely the better choice.

Next, you should consider the accuracy of the gauge. Digital gauges tend to be more accurate than their analog counterparts, but some digital gauges can be less accurate than others. It's important to make sure the gauge you choose will be accurate enough for your needs.

Finally, you should consider the cost of the gauge. Digital gauges tend to be more expensive than analog gauges, but they can be worth the extra cost if you need a high degree of accuracy.

Conclusion

Choosing the right bolt gauge is important for any mechanic, engineer, or anyone else who needs to accurately measure bolts. There are two main types of bolt gauges: digital and analog. Digital gauges tend to be more accurate, but they can be more expensive. When choosing a gauge, it's important to consider the type of bolts you will be measuring, the accuracy of the gauge, and the cost. With a bit of research and consideration, you can find the right bolt gauge for your needs.

Frequently Asked Questions (FAQs)

1. What is the gauge of a bolt?

A bolt gauge is a tool used to measure the diameter of drill bits, bolts, and other fasteners to determine their appropriateness for use. It may also include rules for measuring length.

2. How do you use a bolt gauge?

To use a bolt gauge, it is typically divided into standard and metric sections. The metric holes are usually in the top row, while the standard holes are in the bottom row. Insert the bolt into the holes on the gauge and find the smallest hole that the bolt will fit into. It's important to check more than once to ensure that the bolt cannot fit into a smaller hole.

3. Is Grade 8 or 12.9 stronger?

Grade 12.9 fasteners are stronger than Grade 8 fasteners. Grade 12.9 fasteners have a higher tensile strength of 180,000 psi, while Grade 8 fasteners have a tensile strength of 150,000 psi. Grade 12.9 fasteners are typically used in high-stress environments and are considered more durable than Grade 8 fasteners.

4. How do you measure bolt tightness?

To measure bolt tightness, after fastening the bolt, you can use a torque measuring tool. Apply additional force in the tightening direction until movement is noticed. Recording the torque reading will indicate the residual torque originally applied to the joint.

5. How do you check the tightness of a bolt?

To check the tightness of a bolt, you can: 1) Make sure you've maintained your torque wrench's calibration certificate. 2) Use an impact machine. 3) Establish the bolts' torque value. 4) Inspect the tightened bolts. These steps can help ensure that the bolts are properly tightened and secure.

Editor's Notes

During our bolt gauge research, we found 24 bolt gauge products and shortlisted 10 quality products. We collected and analyzed 19,077 customer reviews through our big data system to write the bolt gauges list. We found that most customers choose bolt gauges with an average price of $26.15.

The bolt gauges are available for purchase. We have researched hundreds of brands and picked the top brands of bolt gauges, including AltitudeCraft, Stainless Town, BoltsandNuts.com, JoblikeBrez, Manalete. The seller of top 1 product has received honest feedback from 161 consumers with an average rating of 4.8.

Written by
Brian Howie Avatar

Brian Howie is a content writer and senior industrial designer. After graduation from Westminster College, he has been engaged in product design and manufacturing for 18 years. Brian Howie has always found great pleasure in designing industrial products and sharing his ideas and experience online.