Topline Wheel Bolt Circle Gauge - Tool Review

While messing around with some of the wheel bolt pattern calculators (Bolt Circle, Bolt Distance) I found this tool on Amazon. It's the Topline C402 Bolt Circle Gauge. This is a really simple and handy tool that makes it easy and accurate to measure a rims or hubs bolt pattern. It's inexpensive and if you do a lot of work on rims and tires it's a good have for the shop.

Note that this is just a handy plastic tool, it's nothing you can't do with a ruler and some information such as the handy-dandy GTSparkplugs paper version of this tool which you can download here -

Pocket Guide to print a handy Ruler to Help Measure 4 and 5 Lug Rims (Inch)
Pocket Guide to print a handy Ruler to Help Measure 4 and 5 Lug Rims (Metric)

Not looking for this, but maybe this is what you need Click For the Bolt Circle Calculator

Topline C402 P.C.D Gauge

Well I don't pretend to know what P.C.D. Stands for but this is the Topline C402 gauge. I picked it up from Amazon and it was under $15. The same tool is available from JEG's as well as other places under their own brand names. It's made of plastic, not cheep not super heavy duty but OK. It's like a plastic caliper of sorts.

Reading the Topline Gauge

It's pretty easy, you find the number of Lugs (on the left) and if you are looking for Metric or Inch (Inch is denoted by a + and metric by a |. The guide also has indicators to what the wheel bolt count is (right above the pencil point is 5 for 5 lug). This shows an 'inch 4.5' pattern which in this case was measuring a Ford wheel.

Measuring from Stud to Stud

The tool has open ends on the back side for helping to center studs for measurement. This is a very convenient features and makes for quick and accurate measurements.

Topline C402 Wheel Circle Gauge Conclusion

While this tool is not something you would use a lot if you are not in the wheel and tire business, it is handy if you are looking to find the bolt patter that you need if you have rims with multiple patters or if you are going swap-meeting to find parts for hubs, rotors, wheels etc. It's inexpensive and that alone is a nice features. That all being said feel free to print out the above GTSparkplugs poor man's version of the tool that you can make and use for yourself like I did. Check out the Automotive Calculator Section for more wheel related tools.

Closer Look at the Topline C402

It can function 2 ways, one is to measure the wheel bolt circle of a rim and the other is to measure the studs coming out of the hub. Reading is a bit tricky at first, but you get the idea after looking at the legend.

The GTSparkplug Wheel Circle Guide

I printed one of the GTSparkplug Wheel Circle Guides out and sandwiched it in a piece of packing tape. Guess what it also reads 4.5" for this hub, so the free version works fine too. It's a bit hard to hold and take a picture at the same time, but if you don't need a tool, but fancy an easy way to determine wheel bolt patter size you can download the paper version for free and make your own. Inch and Metric are both supported from these links -

Pocket Guide to print a handy Ruler to Help Measure 4 and 5 Lug Rims (Inch)
Pocket Guide to print a handy Ruler to Help Measure 4 and 5 Lug Rims (Metric)