Search  for anything...
Thread Checker

Thread Checker Nut and Bolt Checker 23 Inch Sizes and 21 Metric Sizes Bundle with a Lumintrail Keychain Light

    • Based on 406 reviews
Condition: New
Checking for product changes
$63.95 Why this price?

Buy Now, Pay Later

As low as $10.66 / mo
  • – 6-month term
  • – No impact on credit
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout. Payment plans are offered through our trusted finance partners Klarna, PayTomorrow, Affirm, Afterpay, Apple Pay, and PayPal. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

This item is eligible for return within 30 days of receipt

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

Availability: In Stock.
Fulfilled by Amazon
Arrives Sunday, Dec 29
Order within 10 hours and 37 minutes
Available payment plans shown during checkout

Style: Inch & Metric


Features

  • Includes 23 Inch Sizes part number SWTC-S21: 6-32, 6-40, 8-32, 10-24, 10-32, 1/4-20, 1/4-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 7/16-14, 7/16-20, 1/2-13, 1/2-20, 9/16-12, 9/16-18, 5/8-11, 5/8-18, 3/4-10, 3/4-16, 1-8, 1-12
  • Includes 21 Metric Sizes part number SWTC-M21: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M7x1.0, M8x1.0, M8x1.25, M10x1.0, M10x1.25, M10x1.5, M12x1.25, M12x1.5, M12x1.75, M14x1.5, M14x2.0, M16x1.5, M16x2.0, M20x1.5, M20x2.5, M24x2.0, M24x3.0
  • Each Thread Checker as a nut and bolt checker on the same gauge
  • Thread sizes stamped on each gauge for easy identification
  • Bundle includes SWTC-S21 Inch Thread Checker, SWTC-M21 Metric Thread Checker, and a Lumintrail Keychain Light

Description

Thread Checker Nut and Bolt Checker 23 Inch Sizes and 21 Metric Sizes Bundle with a Lumintrail Keychain LightIncludes 23 Inch Sizes part number SWTC-S21: 6-32, 6-40, 8-32, 10-24, 10-32, 1/4-20, 1/4-28, 5/16-18, 5/16-24, 3/8-16, 3/8-24, 7/16-14, 7/16-20, 1/2-13, 1/2-20, 9/16-12, 9/16-18, 5/8-11, 5/8-18, 3/4-10, 3/4-16, 1-8, 1-12Includes 21 Metric Sizes part number SWTC-M21: M3x0.5, M4x0.7, M5x0.8, M6x1.0, M7x1.0, M8x1.0, M8x1.25, M10x1.0, M10x1.25, M10x1.5, M12x1.25, M12x1.5, M12x1.75, M14x1.5, M14x2.0, M16x1.5, M16x2.0, M20x1.5, M20x2.5, M24x2.0, M24x3.0


Manufacturer: ‎Thread Checker


Part Number: ‎SWTC-M21+SWTC-S21


Item Weight: ‎2.38 pounds


Package Dimensions: ‎9.57 x 8.7 x 1.65 inches


Batteries: ‎1 Lithium Metal batteries required. (included)


Style: ‎Inch & Metric


Batteries Included?: ‎Yes


Batteries Required?: ‎Yes


Battery Cell Type: ‎Lithium Metal


Date First Available: September 15, 2020


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Dec 29

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • PayTomorrow Financing
  • Financing through Apple Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews

    • Pricey but convenient
Style: Inch & Metric
Nice pretty complete set. The wire string is at times nice and at other times a pain. But it is one of those things you wished you had bought 20 years ago.
Reviewed in the United States 🇺🇸 on July 6, 2023 by Ryan Arnold
    • Useful, but overpriced
Style: Inch & Metric
Review Image by winterdoesreview winterdoesreview
Review Image by winterdoesreview winterdoesreview
Review Image by winterdoesreview winterdoesreview
The media could not be loaded. This is a handy tool to have for quickly checking threads for organizing nuts and bolts or other purposes, but there are just too many downfalls in quality and design to justify the steep price on these. The threads are accurately cut and the tool does its job well. - What I dislike most about this product is that this is the "comprehensive" set yet there are still many sizes missing. They may not be conventional, but that's why we bought this set and not the smaller, cheaper one. Missing sizes: #12-24 (old machine screws) 11/16-18 M9-1.25 (connecting rod bolts) M11-1.5 (brake line nuts) Almost all extra fine threads All pipe threads And more - Paint on the metric set rubs off very easily. I thought they forgot to paint some of them from the factory and then I realized I just rubbed the paint off by handling it. Ideally, the markings could be bigger too, namely on the bigger sizes. - The wire rope is unwieldy. Too thin, too long, and too much extra length. With all the sizes, each set is just too heavy to handle and gets annoying. I split my kit into two wires for each measurement system using thicker 3/16" (4.7mm) uncoated wire rope, swage stops and a hydraulic crimper (cheaper than you're thinking) - much better; though I should've looped one side. If I can dream up a way, I intend to vinyl coat one end to prevent fraying and then install some sort of removable stop, I could imagine using a set screw or a clamp. - The bolt checking side needs to have more threads. First, the wire rope travels through this part of the tool, so you lose the couple threads at the bottom. Second, some bolts have significant chamfers or worn threads on the end and about 5% of my hundreds of fasteners I couldn't identify confidently. - The beads make me feel like this is something I bought from Etsy, but that's a personal hang-up (as is the uncanny resemblance to a spine). What I don't like about them is that they just take up too much room. This tool could take up a lot less space if they used washers or something. There's extra space on the wire rope, so there's no need to space them out from each other much besides an inch or two (2.5-5 cm) total to pick the smaller sizes out easily. - Tolerances are lacking. Wall thickness varies from piece to piece. The holes drilled though each checker have some variance in diameter in them, even on the same piece. The chamfers are also off on some. Regardless, the holes are just too big for the thin wire rope these come attached to, probably to aid assembly times. Normally I would not acknowledge this but at this price point, this is a premium product and nonetheless - why brag about domestic manufacture if you don't hold yourself to a higher standard? - The pieces are not removable. I could imagine (update: have encountered) a scenario where you would want to test a deep, threaded hole in a small cavity - not happening with this setup. Ideally, it would have a loop on one end and a removable stop on the other. Overall, I would recommend this if you have a lot of hardware to sort through; understand that you probably won't be able to identify everything. If you're sorting through specialized components like engine internals, tiny electronics hardware, fuel system adapters, pipe adapters, agricultural equipment, or other less common threads then you won't be able to identify them. Despite my whining, I generally like the design which keeps all the pieces together, namely, in order, and you don't need a hard case or other bulky storage for it - you just hang it by the loop or toss it in your toolbox. At the end of the day, $60 is hard ask for what is essentially bolts on a wire that was assembled probably to the tune of $5, but it could save you hours if you do lots of organizing. ... show more
Reviewed in the United States 🇺🇸 on July 21, 2021 by winterdoesreview winterdoesreview
    • Handy Thread Checker
Style: Inch & Metric
I had always wanted a way to check threads on fasteners. I considered getting one of those boards from Lowes/Home Depot with studs and threaded holes. This thread checker is so much better. You can use it on a workbench or take it to the fastener of hole. I have both the standard and metric thread versions. I also have the large set with the larger threads. Overall, I love it. ... show more
Reviewed in the United States 🇺🇸 on January 21, 2022 by Amazon Customer
    • A real time saver
Style: Inch & Metric
Well made item that offers comprehensive coverage for identifying threaded components. This is an excellent gift for mechanically inclined people. This purchase exceeded my expectations.
Reviewed in the United States 🇺🇸 on July 18, 2022 by Penny
    • What is that nut or bolt?
Style: Inch & Metric
I inherited a work bench with lots of drawers full of stuff. Wish i had these thread chechers when i started going through all the bolts and nuts. Now i can recheck what i think they are. I could guess the SAE but metric i needed really helped.
Reviewed in the United States 🇺🇸 on April 4, 2022 by DB Grange
    • very useful
Style: Inch & Metric
Well made and easier to use than the plastic thread checkers. I have used it numerous times and I am very pleased with it. Only two negatives for me. The writing on the SAE is a bit hard to read for my aging eyes and the SAE doesn't have #12 thread size which through me off for a minute as the car I am restoring has numerous #12 bolts. Not a #10, 1/4 or metric.....must be a #12! ... show more
Reviewed in the United States 🇺🇸 on May 25, 2021 by ernest mccallum
    • Accurate Bolt/Thread & Nut Checker is Well Made
Style: Combo Inch & Metric
I have used plate Bolt Checkers for years and noticed that they only provide a couple of threads to size the bolts. With this unit you can actually turn the bolt several turns to make sure they don't out of the ordinary wobble. The bonus over plate checkers are you can check both bolts and nuts. They are well-marked, cover the sizes of usual automotive and home project bolts and nuts and are on a single steel cable to keep them from getting lost. The keychain flash light is an extra which I didn't really need but it too works. ... show more
Reviewed in the United States 🇺🇸 on August 24, 2020 by Steven G.
    • Great way to check nuts and bolts.
Style: Inch & Metric
Over the years I’ve collected hundreds of nuts and bolts. Some being standard, some metric. In an effort to get organized I started separating them by sizes. This thread checker is a great tool for identifying sizes correctly.
Reviewed in the United States 🇺🇸 on March 25, 2022 by Jack T Wishlinski

Can't find a product?

Find it on Amazon first, then paste the link below.