Do NOT use Lancelot® or Squire® Saw Chain Blades, products of King Arthur’s Tools®, on any 4"(100mm) angle grinder that requires safety guard modification as described below. This includes any and all 4" (100mm) Makita grinders that need the safety guard adjusted by drilling an additional hole in the body of the grinder.

As a matter of policy, we are immediately withdrawing our recommendation and support for use of any 4"(100mm) angle grinders as described below. Our customers have confirmed this fact. Most have purchased another angle grinder. The difficulty in adjusting the position of the safety guard to the "Correct" position as well as the grinder's lack of power and performance with our cutting blades has led to this irrevocable decision. We do, however, strongly recommend use of 4-1/2" (115mm) angle grinders with a constant pressure switch (paddle, kill or dead man switch). Refer to FAQ’s, Angle grinders, Can you recommend any specific grinders?

Performance and safety are our utmost priority concerns, however, under no circumstances will King Arthur’s Tools take responsibility for any incident arising from improper use of our accessories or ignorance of our recommendations and instructions.

As a commitment to our high level of customer service, these conversion instructions are on our website upon request from users who choose to use this model grinder at their own risk and are aware of our warning. Our recommended alternative choice is NOT to use the 4" grinder but to purchase a 4-1/2" (115mm) model.

4" (100mm) Makita Model Disc Grinders
Safety Guard Adjustment for use with KAT Cutters

INCORRECT for KAT blades	CORRECT for KAT blades
Disassembly Remove locking nut, any accessory (e.g., grinding wheel) and bottom arbor plate from the shaft. Loosen 2 Phillips head screws which secure the safety guard and rear support/ auxiliary handle to the grinder. Screws are located at the top and bottom of safety guard. Place all parts to one side. By removing screws, it releases 1) the safety guard and 2) rear support/auxiliary handle positioned behind safety guard. The two predrilled screw holes are now visible in the body of the grinder. In the newly exposed section of the grinder body you will see a raised round section in the middle of the two holes and to the right, where the new hole will be drilled. Realign rear support in original position over the two predrilled holes and mark center hole in body of grinder. Makita has left an area for this screw position. Using an "11/64" drill bit or a bit slightly smaller than the Phillips screw, gently drill a hole into the grinder. Reassembly Align rear support/auxiliary handle over original two holes. Position safety guard over rear support and turn it counter-clockwise so that the bottom of the guard is approximately level with the bottom of the body of the grinder. The middle and bottom holes of safety guard must line up with the top and the middle holes of rear support. DO NOT REMOVE SAFETY GUARD OR AUXILIARY HANDLE. Using Makita supplied screws (2), tighten safety guard and rear support to grinder as described above in new position. Safety guard is now secured in correct position at approximately 45 degees for use with Lancelot or Squire. Screw backing arbor plate over center shaft, fit any one of the 5/8" (16mm) Lancelot or Squire center hole cutting blades over shaft to seat on arbor backing plate, then tighten securely, screwing Makita lock nut over top disc of blade using the two Makita spanner wrenches. Recommended These angle grinders have either a 3/8" or 10mm threaded shaft with a 5/8" (16mm) arbor on threaded backing plate which screws over shaft. Any individual 5/8" (16mm) center hole blade, e.g. Lancelot 45822, 45814 or Squire 35818, 35812, can be used. Not Recommended These models have no 7/8" (22mm) arbor and are not designed for 7/8" or 22mm accessories. They are also not suitable or adaptable to any tandem blade combination. Points to Note Arbor fit is extremely tight on 45822-45814-35818-35812 bottom disc. While disc will secure, it generally takes a tap or two with a hammer (or similar) to remove this disc. The solution is to take a round file and lightly run inside Lancelot’s bottom disc center hole about 5-6 times. No damage is done nor is safety compromised and insures a proper fit. The objective is to open the hole by a hair, i.e., 0.003 to 0.005. thousands (of an inch). The motor is not very powerful and frequently stalls and cuts out during operation forcing user to use reset switch on bottom of grinder before pressing on switch. Safety Footnote The thumb controlled on/off slide switch must be frequently checked and cleaned of debris, i.e., wood shavings, chips, sawdust, which can accumulate under the "off" section of the switch. Failure to keep clean may result in intermittent or faulty switch operation due to this accumulation of debris under the switch. During operation when user depresses to "off" position, motor and blades will keep running because switch does not engage to "off". It may take several attempts turning switch on and off before stopping. Our recommended alternative choice is NOT to use the 4" grinder but to purchase a 4-1/2" (115mm) model.