Kreg Tool Door Hinge Routing Jig with 1/2-in. Straight Router Bit for 2-1/2-in. to 5-in. Hinges (KRTHJ100)

The Kreg KRTHJ100 Door Hinge Routing Jig is a door hinge routing jig built for cutting hinge mortises and routing door latch locations with a handheld router. This is a router accessory jig designed for door hinge mortising and latch routing. If you install doors, replace hinges, or do punch-list carpentry, this jig gives you a faster and more repeatable way to get clean, flush hinge recesses without relying on a chisel for the whole job. Model Number: KRTHJ100.

What makes this jig useful is how much setup work it removes from the process. It adjusts for hinge lengths from 2-1/2 inches to 5 inches, so it covers the hinge sizes you are most likely to see in residential door work. Kreg also built in precise depth settings for mortising, which helps you get consistent hinge depth from door to door. When hinge leaves sit flush, the door hangs better, closes cleaner, and needs less messing around during final adjustment.

The Kreg KRTHJ100 Door Hinge Routing Jig also handles more than hinge pockets. It is designed to accurately rout latches for 1-3/8 inch and 1-3/4 inch doors, which makes it a more complete door installation jig instead of a one-task accessory. For remodelers and trim carpenters, that means one setup system can cover two of the most common routing operations in door prep.

Kreg includes a 1/2 inch straight router bit with a 1/4 inch shank, so you can get to work without hunting down the correct bit first. There is also onboard router bit storage, which is a small detail but a useful one on the job because loose bits disappear fast. When the accessory stays with the jig, setup is faster and there is less chance of leaving a needed part behind.

From a build standpoint, the jig is made from impact-resistant polymer. That is the right material choice for a tool like this because it keeps weight down, stands up to regular jobsite handling, and is less likely to damage finished work than a hard metal body. The GripMaxx clamp surface is there for the same reason. It helps secure the jig without marking the door surface, which is a big deal if you are working on painted slabs, stained doors, or prehung units that are already close to finish stage.

Compatibility is straightforward. The jig is designed around a 1/2 inch straight router bit with a 1/4 inch shank, and Kreg specifically lists compatibility with the Kreg 1/2 inch Flush Trim Bit - 1/4 inch Shank. That gives you a clear path for replacement or backup bits if you use the jig regularly. The included latch templates also match common residential door thicknesses, so the system is aimed squarely at standard door prep rather than specialty commercial hardware work.

This is a smart fit for carpenters, remodelers, door installers, maintenance crews, and serious DIY users who want cleaner results than freehand routing and faster work than laying out every hinge by hand. If you only hang one door every few years, it still makes the job simpler. If you hang doors often, it saves time where time usually gets wasted: measuring, repositioning, and fixing hinge mortises that are just a little off.

Bottom line: this jig matters because hinge work is one of those jobs where small errors show up immediately. A hinge mortise that is too deep, too shallow, or slightly out of place affects reveal, swing, and latch alignment. The Kreg KRTHJ100 Door Hinge Routing Jig is built to reduce those errors and speed up the part of door installation that usually takes more patience than it should.

Why the Kreg KRTHJ100 Door Hinge Routing Jig earns a spot in the install bag

This is the kind of jig that pays for itself by cutting out layout mistakes and making door prep look more like planned work and less like repair work.

• Who it's for: Carpenters, remodelers, maintenance pros, and serious DIY users hanging doors or replacing hardware with a router.
• Why it stands out: It covers common hinge sizes, includes the router bit, handles latch routing for common door thicknesses, and uses a non-marring clamp surface that makes sense on finished doors.
• Worth knowing: This is a jig, not a complete door hanging system. It speeds up hinge mortising and latch routing, but square-corner hinge work still needs a chisel.

• What hinge sizes does this jig support? It adjusts for hinges from 2-1/2 inches to 5 inches.
• What door thicknesses can it route latches for? It includes latch templates for 1-3/8 inch and 1-3/4 inch doors.
• Does it include a router bit? Yes. It includes a 1/2 inch straight router bit with a 1/4 inch shank.
• What bit is it compatible with? Kreg lists compatibility with a 1/2 inch straight router bit with a 1/4 inch shank, including the Kreg 1/2 inch Flush Trim Bit - 1/4 inch Shank.
• What is the jig made from? The body is made from impact-resistant polymer.