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Hammond & Company Ltd
Finway Road
Hemel Hempstead
Hertfordshire
HP2 7PT
England
+44 (0)1442 212 211
+44 (0)1442 252 003
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We'll respond within 48 business hours
Diagram

Ventec Drills


The problems of twist drilling deep holes are well known in the engineering industry. Drill wander, poor size control and surface finish, flank wear, binding and breakage are occupational hazards. The operation can be slow and inaccurate in the extreme.

An alternative is the use of Ventec drills which are designed to bring the benefits of gun drilling technology to conventional machine tools. Now for a relatively small outlay, it is possible to equip your machine shop with a system that provides a deep hole drilling capability, which in terms of speed and accuracy, equates favourably with gun drilling.

In operation the tool must be supported in a short pilot hole before drilling commences. Thereafter, penetration is continuous and depth to diameter ratios of up to 100:1 are achievable. The cutting forces created by the offset tip geometry act upon the carbide bearing pads, burnishing the workpiece and achieving fine surface finish and size control. It is this accuracy of dimensional control which is responsible for the excellent concentricity achieved by a Ventec drill. It has literally nowhere to go but forward.

Spraymist


The HA3000 Spraymist units can be quickly fitted to most machine tools to give a deep hole drilling capability; they are portable and require only to be connected to the factory compressed air supply. The Ventec drilling system using a Spraymist unit works in the following way. A 3:1 air driven pump situated inside the Spraymist unit pressurises a 10% solution of water and Ventec cutting oil. This fluid is atomised by the compressed air at an adjustable sprayjet head and delivers the resulting mist mixture into the toolholder and through the Ventec drill. At the cutting face the mist mixture expands as it exits the hole in the carbide tip producing a refrigerating effect. The heat from the cutting process evaporates the water content of the mist leaving high lubricity oil to lubricate the burnishing pads of the cutting tip. The compressed air ejects the chips back along the drill flute and out of the hole.

The incoming air pressure should be 5,5-8,5 Bar (80-125psi). The coolant pressure should be set 3-5 Bar (45-75psi) above this pressure. The mist flow should be adjusted until a light mist is visible at the commencement of drilling. During the drilling cycle a trickle of fluid should just be noticeable returning along the drill shank and slightly wetting the face of the workpiece. To achieve optimum results the Ventec cutting oil mixing instructions must be followed exactly.

For full set up instructions see our video below.

We also offer a range of standard and custom built Coolant Fed Toolholders. For further information, please see our accessories.

Spraymist/Ventec Instructional Video

Ordering Information


Please specify the drill diameter and flute length. The flute length should equal the hole depth plus 2 x diameter. This allows for re-grinding. If holes are deeper than 30 diameters they should be drilled in 30:1 stages. The driver size will be fitted according to the chart below.

For full ordering details required see Product Codes.

Drivers


Driver Styles   Ref Tip Diameter Ød h
Overall Length
View PDF
VT1 CA Ø5.0 - 11.73 Ø16 40 Flute Length + 50.0
VT2 CB Ø11.74 - 21.18 Ø25 50 Flute Length + 65.0
VT3 CC Ø21.19 - 40.50 Ø35 60 Flute Length + 80.0

Cutting Data


Material Surface Speed
Metres
Feed
/Rev
Ø6.0
Feed
/Rev
Ø8.0
Feed
/Rev
Ø10.0
Feed
/Rev
Ø15.0
Feed
/Rev
Ø20.0
Feed
/Rev
Ø30.0
High Temp Alloys 18 0.010 0.012 0.015 0.020 0.025 0.030
Stainless Steel Alloys 30 0.015 0.020 0.025 0.035 0.040 0.040
High Carbon Steel 38 0.015 0.020 0.030 0.040 0.050 0.050
Medium Carbon Steel 45 0.020 0.030 0.040 0.050 0.060 0.060
Low Carbon Steel 55 0.020 0.030 0.040 0.060 0.075 0.075
Cast Iron 35 0.040 0.060 0.100 0.130 0.150 0.180
Free Cuttin Alluminium 75 0.040 0.060 0.100 0.130 0.150 0.180

Clamping Method
Face Horiz Vert Horiz Vert
A +20° +15° +22° +13°
B +19.5° +20° +21.5° +18°
C -15° +15° -13° +16°
D +25° +25°
E -18° -14° -20° -12°
Good surface finish required on faces A, C and Chamfer.
DRILL
DIA.
PRIMARY
RELIEF
CHAMFER
AT 20°
Ø5-Ø12 0.4 - 0.6 0.4 - 0.6
Ø12-Ø25 0.6 - 0.8 0.6 - 0.8
Ø25-Ø40 0.8 - 1.2 0.8 - 1.2