How to Know the Key Size for a Drill Chuck

How to Know the Key Size for a Drill Chuck

In the tools of any home master, a drill must be present. True, sometimes it becomes necessary to remove a cartridge from it. As a rule, such a problem arises when the device breaks down.

Any craftsman who understands at least a little bit of technique will be able to complete this task. But for a person who has never encountered this, it can be a big problem. To easily remove the part from the drill, you first need to study the principles of its fastening, and only then proceed with the replacement.

Cartridge classification

Exist several of their varieties:

  • Keyless types;
  • Collet SDS devices;
  • Cam types.

In quick-clamping elements, changing the bit or drill will turn out in seconds, without using any additional tools. They are divided into single and double coupling types.

In the latter version, to attach the drill with one hand, you have to hold the sleeve, and the second screw the other. In one-foot cartridges there is a shaft locking system that is triggered when replacing equipment. The disadvantage of such products is low fixation strength drills. In addition, the use of plastic parts significantly increases the risk of damage to the cartridge.

It is better to put cam cartridges on percussion drills and perforators. They are stronger, so they are often used to work in difficult conditions. In such products, plastic elements are not installed, and the fastening of snap-ins is carried out with a special key.

There are also collet SDS cartridges that were created in the 70s of the last century. There are two grooves in the shank of this design, the size of which is 10 mm.

In this system, part of the drill has to be screwed into the cartridge by 40 mm. It is fixed with locking balls. In addition, in the design there are 4 grooves, 2 of them are fixing, and the rest are used for guide wedges. The spindle of a device equipped with this design is automatically locked immediately after installation.

Mounting Methods

In any drilling tool, the chuck on the shaft is fixed by two methods: on the cone and using a threaded fastener.

In the latter embodiment, there is an inch or metric thread on the inner channel and shaft of the drill. In this situation, when repairing, many often have the question of how to change the cartridge for a drill. You can find out the type of thread and its characteristics on the body. For example, if 1-15M13x1.3 is knocked out, then it means:

  • M13. diameter metric thread;
  • 1.3 is her step;
  • 1 and 15. the maximum and minimum size of the drill shank.

Video: How to Know the Key Size for a Drill Chuck


When inch threads are used, the UNF designation is marked. Therefore, before changing the product, it is necessary to check whether the mounting dimensions correspond to the marking. Now almost all drills have an inch thread.

For tight connection, a locking screw is mounted on the shaft inside the device. It has a left-hand thread, in other words, it should be unscrewed clockwise.

Another fixation option involves application of morse cone. The end of the motor shaft is made in the form of a cone. The same conical part has an internal channel. Install the cartridge on the shaft cone. These elements are marked as B 10, B 12, B 16, and also B 18. A particularly similar method is popular in screwdrivers.

Dismantling the threaded chuck

To remove it you will need a screwdriver. She loosens a screw that is screwed into the tool spindle and installed inside the product. Then he twists from the spindle. As mentioned above, the internal screw has a left-hand thread, therefore, it rotates clockwise. True, the cartridge unscrews counterclockwise, since it, on the contrary, has a right-hand thread.

If the screw does not want to loosen, tap on it. through a screwdriver with a hammer. There should not be any difficulties with the cartridge; it can be easily twisted. Although in case of difficulties, you can use a wrench and gas wrenches. Attach the spindle to the drill first, and grasp the chuck last.

In addition, when the chuck operates on the chuck, a thicker hexagon can be installed to invert it. You also need to fasten the spindle with an open-end wrench. On most modern battery-powered drills, additional attachments are not required to secure the drill. However, changing the cartridge to them is very difficult.

When this doesn’t help to remove it, disassemble the tool body. Thus, it is possible to reach the spindle, since it is hidden when assembled. Then everything is collected back, but without the use of keys.

What should I do if the internal screw is damaged during the replacement process? In this situation, it is better to purchase an adapter for a cartridge for a cam type hammer drill, since a screw is included with it.

How to replace a conical instance?

Difficulties in removing the element mounted on the shaft cone should not appear. You can use a special device that is used to replace bearings.

But the easiest way is to place the tool vertically, while the drill will look down. Then you need to tap gently over the entire surface with a hammer until the cartridge breaks out of engagement. If necessary, grinding is performed. The new part is inserted with light strokes from above.

Drill change in drill

Often due to excessive load or improper fastening, the drill is capable of jam cartridge, in the usual way to get it will not work. What to do in this case? First, just try to cool the part. Quite often, this is enough to relax the fists and pull out the drill.

You can go the other way. To relieve jammed equipment will help tapping the fists. To do this, in the vice should fix the free edge of the drill and attach wooden plank to the cartridge. It is through her that tapping is performed. The chuck will loosen its grip from vibration and the drill can be easily removed. over, this method is suitable for owners of quick-clamping and classic fasteners.

But sometimes it is impossible to remove the tool without using grease. In particularly difficult situations, it is possible to solve the problem only after immersing the cartridge in vegetable or engine oil. Keep the product in liquid for about an hour. If you combine the methods, then removing the stuck drill will be much faster.