Spraymist Kits

When attached to standard shop air pressures of 100 to 125 psi, these units deliver lubricant as an atomized mist directly to the cutting edge, forcing chips out of the bore. Lubricant usage is typically less than one gallon for four hours drilling with a 1/2" diameter gun drill.


One gallon (4 liter) capacity



Four gallon (15 liter) capacity


Each Spraymist kit includes:

  • Spraymist kit
  • 8 foot dual hose assembly
  • High flow mist jet
  • Full instructions

Watch the video for a demonstration.


Spraymist kits are specifically designed for carbide tipped, coolant fed drills to produce precision and deep holes. The kit consists of a pneumatically operated piston pump delivering air and pressurized lubricant through a flexible dual hose assembly and a high flow mist jet. Spraymist is fed through one or more drills during operation. The system is manually operated by a slide valve at the air inlet.

Automatic control is achieved by substituting a solenoid valve (DM-66) in place of the slide valve and interconnection with a machine control.

Principle of Operation

A portion of the incoming air supply operates an internal piston pump delivering lubricant at 1.5 times air line pressure into the air stream. The positive injection of lubricant creates a continuous atomized mist. In operation, the cooling and lubricating action of the spraymist draws heat from the surrounding material, cools and lubricates the drill tip, and forces chips out from the bore.


Sterling Gun Drills' DM2000 and DM3000 Spraymist Kits are suitable for most machine tools from manual lathes and milling machines to CNC turning and machining centers. Some manual machines with a limited speed and/or feed range will be more suitable if modified to achieve a workable rate. Vertical machines must be measured for clearance between the work piece, drill and toolholder.

Spraymist Kits are an element of the Sterling Gun Drills Deep Hole Drilling System along with Gun Drills, Half Round Drill, and the TWINMASTER™ drill used with Rotary and Stationary Toolholders, Lubricant, and Re-Sharpening Fixtures. The Sterling Gun Drills system is portable, allowing deep and/or precision holes to be completed in house without relocation of the workpiece during regular machining operations. Spraymist is often a practical and economical alternative to high pressure pumping system retrofits or farming out work to gun drilling contractors. An additional benefit is that experience gained by in-house deep hole and precision drilling allow manufacturers to expand their range of operations and quoting opportunities.

For Expert Technical Advice, Call Sterling Gun Drills.
Toll Free: 1-888-338-1049

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Spraymist Operating & Service Instructions

Set-Up Instructions

Place the spraymist unit within reach of the toolholder by the 8' dual hose assembly supplied. Connect the slide valve to the 1/4" NPT air inlet.

Press in the larger "Air" hose into the lower connector on the manifold, and the smaller "Fluid" hose into the upper.

Fill reservoir with the appropriate cutting fluid (see notes) mixing in a separate container at a 10:1 ratio.

Connect the high flow mist jet to the toolholder or delivery device for the drill.

Shop air supply 100 psi minimum.

Important Notes

Fill reservoir with Sterling Gun Drills lubricant (DF-81, DF-86) or equivalent high "EP" oil base water soluble coolant.


NEVER rotate the drill outside of the drilled hole or pilot hole.

Do not allow a filled unit or the lubricant to freeze.

If a drill breaks, turn off the slide valve and remove the mist jet prior to removing the drill.

For extended periods of non use, drain and rinse the reservoir and cycle the pump to clear residual coolant.

Air Vol.: 4-8 CFM, dependent on drill size.


Prepare a pilot hole to the drill diameter +.001", -0 by 1/2 to 1 diameter deep. The shape of the hole bottom is of not important. If a bushing is used, keep it to +.001" and against the part if possible.

With the drill secured in the toolholder, open the slide valve to actuate the unit. Press the "reset" button on the enclosure top to provide the initial charge of lubricant. Check that the pressure on the output gage is approx. 50% higher than your known shop air supply. The "reset" should be required once at the start only, then the pump will cycle as required depending on coolant usage, typically once every 30 to 60 seconds.

Adjust the high flow mist jet volume with the knurled knob to develop a very fine mist. Typical lubricant usage should be about one gallon per four hours of drilling with a 1/2" drill. Note: Too much mist interferes with cooling and chip removal.

Enter the drill into the pilot hole or bushing. Start the spraymist, spindle, then the feed (set to the rates given on our universal speed & feed chart) Drilling is continuous to depth, no peck cycle required.

At depth, stop the feed and retract slightly if a blind hole, then stop the spindle, the mist and then back out.

Optional Automatic Operation: CNC - Replace the slide valve with the DM-66 solenoid valve and program the machine control to turn the spraymist unit on and off.

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