Custom exhaust has a way of finding the one spot where a straight tube will not fit. There is a crossmember in the way, a header tube needs a tighter turn, or your intake route wants to occupy the same space as something expensive. Time to build a bend.
Pie cut templates help you mark the angled sections that can be assembled into that bend. KMC templates slip around straight metal tubing, giving you an edge to trace instead of laying out every cut from scratch. Choose the right size, angle, and radius, mark the tube, remove the template, and make your cuts. The fit-up afterward still deserves your full attention.
A KMC template fitted around straight tubing before the cut lines are marked.
What pie cut templates actually do
A pie cut is a wedge-shaped section of tube. Arrange those sections together and the tube changes direction at each joint. That gives you another way to build a custom route when a straight section or an available preformed bend does not suit the job.
The template handles the marking part of that process. It is a layout tool; you remove it before cutting. The resulting bend comes from the metal sections you cut, fit, and weld together.
That distinction matters when you are shopping. The rings shown here are templates, not metal pie cut sections that get welded into the exhaust.
Choose the template that matches your tube
Measure the actual outside diameter of your tubing first. KMC pie cut templates are offered for 1.75, 1.875, 2, 2.5, and 3 inch tubing. A nominal pipe size is not a substitute for that measurement. A template needs to fit the tube you are holding, not the number you remember from the invoice.
Next, choose the pie cut angle and centerline radius. KMC offers 9, 15, and 22.5 degree templates, with 1D and 1.5D radius options in specific size combinations. Those are separate choices: the angle describes the wedge, while the radius describes how tight the planned bend is.
Plan the route before marking the tube
Work out where the bend needs to start and finish, which way it needs to turn, and what it needs to clear. Leave room for the connections and the way the assembly will be installed. A bend that looks great on the welding table can still be a pain to get into the car.
A reference line along the tube can help you keep the pieces oriented during layout and fit-up. For a bend that stays in one plane, that reference gives you something consistent to line up. If the route changes planes, make that change deliberately and track the orientation of the sections.
Slip on the template and mark the cuts
Clean the marking area so your lines are easy to see. Slide the matching template over the tubing and settle it into position without forcing it. Keep it steady while you trace the appropriate profile.
Use a fine, visible line and check that it stays consistent around the tube. A thick marker line is useful for visibility, but it also leaves you more room to wonder which side of it you meant to cut.
KMC templates have alignment markings at 22.5 degree intervals around their circumference. Use them as references when positioning the template. Those alignment marks serve a different job from the 9, 15, or 22.5 degree pie cut angle printed on the template.
Marked and numbered sections help keep the layout organized. The tube in this photo has not been cut.
Number the sections while you can still see how everything belongs together. Mark orientation as well if the route needs it. Once the pieces are loose, a small pile of very similar wedges becomes a surprisingly effective memory test.
Make a test section and check the fit
Remove the template before using a cutting tool. Use equipment and a blade or abrasive suited to the tubing material and wall thickness, and secure the work appropriately. The template supplies the layout, not the cutting setup.
Start with a test section when you are learning a new template or changing your cutting setup. Check how your cut follows the line, account for material lost to the cut, and clean up the edges without casually changing the angle.
Bring the pieces together and inspect the fit before producing the rest. If the first joint is off, fix the cause now. Repeating the same mistake six times does not improve it.
Mock up the bend before the final weld
Use your numbers and orientation marks to assemble the sections in order. Check the overall direction, how the ends meet the adjoining tubing, and the clearances in the actual project.
Tack the assembly as appropriate for the material and joint, then check the route again before final welding. Keep access to the welds in mind. A sensible sequence now is easier than trying to reach a hidden joint later.
Final welding preparation and technique depend on the tubing material, thickness, and application. Good layout gets you to the fit-up stage with a plan; the rest of the fabrication still determines the finished result.
Get the templates that suit the work
For one specific combination, choose an individual pie cut template. If you want several angle options for one tubing size, KMC also offers pie cutting template kits, including 3 piece sets, 9 piece radius kits, and an 18 piece Master Kit.
Start with the tubing and the route your project needs. Pick the templates around that. The goal is a useful cut line and a bend that belongs in the build.
Common questions about using pie cut templates
Can the template stay on the tube while cutting
Remove it after marking and before cutting. Use the lines to guide your cutting setup; the template itself is a marking tool.
Are pie cut templates the same as tube notching templates
They lay out different joints. Pie cut templates help mark sections for a bend. Tube notching templates help mark the cope where one tube meets another. For that job, see our guide to notching tubing without a tube notcher.
Do I need the Master Kit for one bend
A single matching template may cover a specific job. A 3 piece kit gives you three angles for one size and radius. The larger kits make more sense when you work across several tubing sizes or want both available radius families.
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