Owner’s manual
Error Codes
How to replace a Craftsman router bit?
To replace a bit (cutter) on your Craftsman router model 315174921, unplug the router, lock the spindle, loosen the collet nut, swap the bit, then tighten the collet nut securely. Confirm the correct steps and safety notes in the 315174921 owner's manual.
- Unplug the router before touching the collet or bit.
- Engage the spindle lock on the front of the motor housing; push it in and slide it into the lock position.
- Loosen the collet nut (turn counterclockwise) while holding the spindle lock.
- Remove the old bit from the collet.
- Insert the new bit into the collet, then back it out slightly (do not bottom it out).
- Tighten the collet nut firmly while the spindle lock is engaged.
- Recheck tightness before powering on.
The manual calls out two critical safety points for this model:
- Never activate the spindle lock while the motor is running or coasting.
- Do not operate the router without the chip shield properly in place.
| Symptom | Most common cause | What we do next |
|---|---|---|
| Bit creeps out during a cut | Collet nut not tight, bit inserted too shallow/deep | Re-seat bit, tighten collet nut firmly |
| Excess vibration or chatter | Dirty collet/collet nut, bent bit, wrong speed/feed | Clean collet, replace bit, slow feed rate |
| Rough cut or burning | “Force feeding” (moving too fast), too deep a pass | Reduce depth-of-cut, slow feed, make multiple passes |
A properly seated bit and clean collet help your Craftsman 315174921 router cut smoothly at high speed and reduce the chance of bit slippage, splintering, or motor overload.
If you need to identify the correct wrench, base components, or other repair parts by model number, we list them for 315174921 on the model parts page and you can also search by model at Sears PartsDirect.
Last updated: February 2026
How to remove collet from Craftsman router?
To remove the collet on a Craftsman 315174921 router, we unplug the router, lock the spindle, then loosen the collet nut counterclockwise with the wrench until the bit slips out. If you need the collet itself out, keep loosening; it releases from the nut as it backs off.
- Unplug the router.
- Set the router upside down on a stable table.
- Push the spindle lock in and slide it into the lock position.
- Use the supplied wrench to turn the collet nut counterclockwise.
- Remove the cutter (bit) once it slips free.
- Keep turning the collet nut counterclockwise to separate the collet from the nut.
- Return the spindle lock to the unlock position so the router can run.
Most Craftsman routers use a “self-releasing” collet nut. As you loosen the nut, you typically feel:
| What you feel | What it means | What to do |
|---|---|---|
| Nut loosens easily at first | Normal loosening | Keep turning counterclockwise |
| A brief “pop” or increased resistance | Collet is breaking free from the taper | Continue loosening steadily |
| Bit slides out | Cutter is released | Remove the bit, then keep loosening if removing the collet |
- Loosen the collet nut a few more turns (do not force it off at an angle).
- Remove the nut and collet assembly, then tap the nut lightly in your palm to free the collet.
- Clean dust and chips from the collet and collet nut, then reinstall.
For the exact spindle-lock and collet-nut procedure and diagrams for this model, use the 315174921 owner’s manual.
A properly released and clean collet grips the bit shank evenly. That reduces bit slippage, chatter, and overheating, and it helps protect the router’s spindle and bearings.
To look up replacement parts by model number and shop our catalog, use Sears PartsDirect.
Last updated: February 2026
What size shank bit will fit in a Craftsman router?
For the Craftsman router model 315174921, use router bits with a 1/4-inch shank. Our manual for this model specifies a precision collet designed to fit cutters with a 1/4-inch diameter shank; using the correct shank size helps the bit clamp securely and run true.
- Verify the package or bit marking says 1/4 in shank (shank is the smooth part that goes into the collet).
- Insert the shank so it is close to, but not touching, the bottom of the collet.
- Tighten the collet nut firmly with the provided wrench.
- Make sure the spindle lock is released before turning the router on.
- If the bit slips, chatters, or leaves burn marks, stop and re-seat the shank and re-tighten.
The manual’s key safety point is simple: never engage the spindle lock while the motor is running or coasting.
- Unplug the router.
- Place the router upside down on a stable surface.
- Engage the spindle lock, then loosen the collet nut.
- Remove the bit; insert a 1/4-inch shank bit.
- Tighten the collet nut securely; return the spindle lock to the unlock position.
| Shank size | Typical use | Fits Craftsman 315174921? |
|---|---|---|
| 1/4 in | Most trim and general-purpose handheld routing | Yes |
| 1/2 in | Larger bits, heavier routers, more rigidity | No |
| 8 mm | Some specialty/European bits | No |
Using the correct shank size reduces vibration, improves cut quality, and helps prevent the bit from slipping in the collet under load (especially when taking deeper cuts or feeding too fast).
For diagrams and the exact bit installation steps for this model, use the 315174921 owner's manual. For parts and accessories searches by model number, use Sears PartsDirect.
Last updated: February 2026
What is a Sears Craftsman router?
A Sears Craftsman router (like Craftsman model 315174921) is a high-speed, corded woodworking power tool used to shape edges, cut grooves, and make precise profiles with a rotating router bit. This model is double insulated and is designed for clean, smooth cuts when fed at the right speed (see the 315174921 owner's manual).
We typically see routers like the Craftsman 315174921 used for common woodworking tasks such as:
- Edge profiling (round-overs, chamfers, ogees)
- Cutting dadoes and grooves
- Trimming and flush-cutting with guide bits
- Making rabbets and recesses
- Pattern routing with a template
From the product documentation, this router is built as a high-speed tool and is intended to produce smooth results when you avoid overloading the motor.
| Feature | What it means for you |
|---|---|
| Double insulated | No grounded (3-wire) system is required; insulation isolates exposed metal parts from internal motor components |
| High no-load speed | Helps produce clean cuts when the router is allowed to run freely |
| Feed-rate sensitive | Pushing too fast can overload the motor and cause rough cuts, splintering, or gouging |
When a router is pushed forward too fast, the bit slows under load and starts taking bigger bites, which makes the finish rougher.
- Use a smaller bit when possible for heavy work
- Reduce depth of cut; take multiple shallow passes
- Slow your feed rate, especially in hard, knotty, gummy, or damp wood
- Listen for the motor pitch dropping; that sound change signals overload
- Keep the bit sharp and the base stable on the workpiece
Using the correct feed rate and depth of cut protects the motor, improves surface finish, and reduces the chance of splintering and gouging. It also helps you work more safely and with better control.
For Craftsman 315174921, the model number is listed on a plate attached to the end cap. Use that exact model number when looking up diagrams or ordering repair parts through the model parts list or by searching on Sears PartsDirect.
Last updated: February 2026
