Drill press spindle, chuck and table care

⚙Care and inspection

• Mount the drill chuck on the spindle taperDrill chuck (taper type)

  Wipe the oil and dirt completely off the taper at the spindle tip and the taper of the drill chuck with a clean cloth. Retract the chuck's three jaws into the body before inserting, then drive the chuck on by striking its end face with a wooden (or plastic) hammer. Do not strike it with an iron hammer (Yukiwa Seiko)

  If there is oil on the taper or the chuck is not driven in far enough, it can fall out, which is dangerous. If it falls out and damages the taper, the spindle can no longer be used (KIRA). Striking it with the jaws protruding can cause poor tightening of the drill (Makita). Wipe off the rust-preventive oil applied at shipping before assembly (KIRA, Makita)^[1][2][3][4]

• Remove the drill chuck from the spindleDrill chuck (taper type)

  Drive a wedge-shaped tool (a wide, tapered tool) into the gap at the boundary between the chuck and the taper, and release the seating little by little (Yukiwa Seiko). For models with a Morse taper spindle, some manufacturers supply a drift as an accessory (KIRA KID-420)

  The chuck is held by contact pressure between the tapers, so it often seizes and will not come off (Yukiwa Seiko). This is dangerous work, so take great care against injury and machine damage. Yukiwa Seiko says that if you cannot remove it yourself, you can send the chuck together with its arbor to the manufacturer to have it removed at the factory^[4][2]

• Tighten the drill in the chuckDrill chuck

  Do not tighten the chuck key (chuck handle) at only one hole. Tighten evenly, a little at a time, at all three holes (Yukiwa Seiko, Makita). Hold small-diameter drills in a chuck with the smallest possible gripping diameter (Yukiwa Seiko). Always remove the chuck key after tightening

  Tightening evenly reduces radial deviation of the tool and grips with good accuracy (Yukiwa Seiko). KIRA also asks that the drill be mounted securely with no runout. As an example, Yukiwa Seiko cites a 5MG-JT1 chuck for a 5 mm diameter drill^[5][3][1]

• Cleaning the chuck, and jaws that will not open or closeDrill chuck

  Do not blow air into the chuck from the jaw side toward the inside. If the jaws stop moving, clean the inside with a cotton swab or the like, or tap the body lightly with a wooden or plastic hammer to shake out the chips inside. Do not disassemble the chuck yourself

  The most common case is that air blowing pushes chips inside and the jaws can no longer open and close. A chuck is assembled by press-fitting its parts, so disassembly is dangerous (Yukiwa Seiko). Yukiwa Seiko says that when the jaws of a keyless chuck seize on the tool, it can be fixed by replacing parts^[4][5](1 source, for reference)

• Keep the chuck accurate for a long timeDrill chuck

  Do not tighten with more force than necessary. Do not apply such a heavy load that the tool slips in the chuck

  Over-tightening damages the tool with the jaws. If the load is so large that the tool slips, the three jaws wear and can no longer grip accurately (Yukiwa Seiko)^[5](1 source, for reference)

• Check the type of spindle taper and match the tool to itSpindle taper

  Check for each model whether the spindle end is a Jacobs taper (JT) or a Morse taper (MT), and use matching tools (chuck, arbor, taper-shank drill). Among KIRA's current models, the NSD-340 bench drill press is JT6 and the KID-420 is MT2 (MT3 is optional)

  Jacobs tapers are mainstream in Japan and the US, while Morse tapers are mainstream in Europe (Yukiwa Seiko). Tools with the wrong taper will not fit. The shapes and dimensions are given in JIS B 4634 for drill chucks and in JIS B 4003 for Morse taper shanks and sockets (bibliographic records of the standards)^[6][7][8][9]

• Changing the belt position and adjusting tensionV-belt and pulleys

  Turn the power off and open the belt cover. Loosen the motor fixing screw (motor clamp bolt), move the motor forward to slacken the belt, and move the belt to the groove that matches the speed. Fit the belt parallel to the pulleys, never at an angle. Pull the motor back to tension the belt, tighten the fixing screw, and close the cover

  Too much tension lowers the speed, shortens the life of the belt and motor, and causes failures. Too little lets the belt slip during work (HOZAN). KIRA also asks that the belt not be tensioned tightly. Keep your hand from getting caught between the pulley and the belt when changing the belt position (KIRA)^{[3][10][1][2]}

  Source	Tension guideline
  Makita TB131	Pressing the belt with a finger at about 5 kg of force deflects it 10–15 mm
  HOZAN K-21	Just enough not to slip. Not too tight
  KIRA NSD-340, KID-420	Do not tension tightly (the KID-420 tensions two belts at once with the spring of an intermediate pulley)

• Choose the speed (belt step) to match the drill diameterV-belt and pulleys

  Larger drills get lower speeds (low-speed step), and smaller drills get higher speeds. Choose the step that matches the drill diameter from the table on the machine's nameplate or in the instruction manual

  KIRA and HOZAN ask that you choose a speed suited to the drill and the work. Makita shows the step for each drill diameter in a table. For how to find the speed, see “Calculating speed and machining time”. For examples of steps per model and applicable drill diameters, see the table “Examples of speed steps and drill diameters”^[3][10][1]

• Set the table height and angle, and lock itTable and column

  Loosen the table's clamp bolt, move the table with the handle to a convenient working height, then tighten the clamp bolt firmly (KIRA). The square tables of KIRA's 340 and 420 series can be tilted up to 45° (the round table cannot be tilted)

  Working with the clamp bolt loose lets the table tilt forward and down or shift, producing slanted holes (KIRA). Lubricate the column outer diameter once a day (KIRA; see the lubrication section). The HOZAN K-21 fixes the body height with a T-screw and asks that it not be pulled up beyond the upper limit^{[1][2][10][11]}

• Secure the workpiece with a vise or clampsWorkholding (vise and clamps)

  Always secure the workpiece with a vise or the like, and secure the vise to the table as well (KIRA). Use clamps or a vise (Makita). On models with a parallel guide, it can also be used to keep the workpiece from rotating (HOZAN). Before working, clear unnecessary items off the table (MHLW near-miss case)

  Machining without securing the workpiece is dangerous, as the drill can swing it around or lift it (KIRA). It is safer than holding it by hand and leaves both hands free to operate the machine (Makita)^{[1][3][10][12]}

• Make a dimple at the hole position before drillingPositioning for drilling

  When drilling metal, make a dimple at the hole position with a center punch and place the drill tip in it (Makita). Make the center hole (centering) with a drill whose point angle is the same as or larger than that of the drill for the main hole. Do not make the centering hole large to double as a chamfer (OSG)

  The drill tip does not slip, and the hole is drilled at the exact position (Makita). If the centering point angle is smaller than that of the main drill, the drill contacts at its shoulder (outer edge) and wobbles, making the hole position unstable (OSG)^[3][13][14]

• Do not force the feed handleFeed (handle)

  Lower the handle slowly, adjusting the force as you drill. Do not lower it suddenly or press harder than necessary. When the hole breaks through, keep a hand on the handle and return it slowly (HOZAN)

  Pressing too hard overloads the machine and stops the rotation, which can deform or break the drill and cause failures (HOZAN). Forcing it does not improve efficiency and shortens the machine's life (Makita). If you let go of the handle, the spring force snaps the spindle back suddenly (HOZAN)^[10][3][1]

• Check the quality of drill regrindingDrill

  After regrinding, keep the difference in height between the left and right cutting edges (lip height) to 0.03 mm or less, and check that the point angle is symmetrical and that the chisel edge is not off-center (OSG)

  Lip height variation or an off-center tip unbalances the cutting, makes the tip wobble, and makes the hole oversized, triangular (polygonal), or bent (OSG)^[15][16][14](1 source, for reference)

▦Examples of speed steps and drill diameters (bench drill press, steel drills)

The speed changes with the power frequency (Makita's table gives separate values for 50 Hz and 60 Hz). The KIRA NSD-340 has 4 steps (50 Hz: 415, 750, 1,330, 2,300; 60 Hz: 500, 900, 1,600, 2,800)^[3][10]

÷Calculating speed and machining time

1. Choose the drill cutting speed V (m/min) from the material (cutting speed table)
2. Calculate the speed n = 1000 × V ÷ (3.14 × D) (D is the drill diameter in mm)
3. From the machine's belt steps, choose the one closest to the calculated value, and check it against the guide drill diameters in the instruction manual
4. Decide the feed f (mm/rev) (feed table), and find the machining time t = 60 × hole depth L ÷ (n × f) seconds

Speed n (min⁻¹)

1000 × V ÷ (3.14 × D)

Cutting speed V (m/min)

3.14 × D × n ÷ 1000 (divide by 1000 to convert mm to m)

Machining time t (seconds)

60 × L ÷ (n × f)

Feed rate vf (mm/min)

f × n

Worked example: conditions

A hole 10 mm in diameter and 20 mm deep in carbon steel (0.4–0.7 % carbon). V = 20 m/min, f = 0.2 mm/rev

Worked example: speed

1000 × 20 ÷ (3.14 × 10) ≈ 637 min⁻¹ → on a Makita TB131, speed 1 (50 Hz: 570, 60 Hz: 690). The machine's own table also puts 10 mm at speed 1

Worked example: machining time

60 × 20 ÷ (570 × 0.2) ≈ 10.5 seconds (speed 1 at 50 Hz)

Worked example: KIRA's quick reference table

Feed 0.18 mm/rev, speed 450 min⁻¹, depth 40 mm → 60 × 40 ÷ (450 × 0.18) ≈ 29.6 seconds

The speed and machining time formulas appear in the same form in KIRA's quick reference table and in Mitsubishi Materials' technical information (Mitsubishi Materials gives the machining time in minutes and multiplies by 60 to get seconds)^{[17][18][19][3]}

▦Drill cutting speeds and standard cutting fluids (HSS drills, KIRA)

Extracted from KIRA's technical reference. The row for the weakest alloy steel grade is not included because its notation is hard to read. Values vary with the drill type (carbide, etc.) and the manufacturer^[17](1 source, for reference)

▦Standard drill feeds (mm/rev, KIRA)

Values for power-feed models. For a hand-feed bench drill press, they serve as a guide to the feel of the feed. OSG gives “drill outside diameter × 0.02” as a guide to feeds that limit hole enlargement (0.2 mm/rev for a 10 mm diameter, which falls within the 8–11 mm range of KIRA's table)^[17][15]