2018 PURROS New Product Launch Ceremmony – PG-F4N Complex Grinder for End Mill and Drill


Some improved performances of PG-F4N is compared with PG-F4

Improved Points as below (PG-F4N Advantages):

1. For grinding drill bit, the maximum grinding diameter increased to φ15
2. Point Angle Grinding Ranges: For End Mill, extended from 0°~5° to 0°~7°; For Drill, extended from 100°~135° to 95°~150°
3. Motor Power: Increased from 180W to 200W
5. Rotating Speed: Increased from 4800RPM to 5000RPM
6. Grinding Wheel: For End Mill grinding, multiple directions can be used; For Drill Bit Grinding, the diameter of grinding wheel is increased to 80mm
7. 2-flutes, 3-flutes, 4-flutes, and drill bit are also equipped their own collect chuck.
8. More accurate presetting cutter device

performances of Complex Grinder PG-F4N is compared with Complex Grinder PG-F4

Earlier Version (PG-F4 Complex Grinder)
Model: End Mill Drill
Ranges: Φ4-Φ14MM Φ3-Φ14MM
Point Angle: 0°~5° 100°~135°
Voltage: AC220V
Power: 180W
Rotate Speed: 4800RPM
Dimension: 37*23*30CM
Weight: 20KG


New Version (PG-F4N Complex Grinder)
Model: End Mill Drill
Ranges: Φ4-Φ14MM Φ3-Φ15MM
Point Angle: 0°~7° 95°~150°
Voltage: AC220V
Power: 200W
Rotate Speed: 5000RPM
Dimension: 46*32*31CM
Weight: 25KG

What are the rewards for drill bit sharpening machines?

the drill bit grinding machines produced by purros are sold all over the world

  1. Save more than 70% of the cost of drill bits


  • 1). Old tools become new tools. A drill can be sharpened at a small cost. It saves you a lot of money.
  • 2). Old tools such as drill bit/milling cutter tool can be grinded and reused.
  • 3). The grinding capacity of each tool is only 0.4mm, and each tool can be grounded more than 10 times.
  • 4). It solves the problem of traditional manual grinding tool (non-standard, short life and long time).
  • 5). High grinding precision, extend tool’s life.
  • 6). It can not only grind high-efficiency drill bit, but also can grind common drill bit into high-efficiency drill bit.


  1. Improve machining efficiency by 3-6 times

  • 1). It takes an average of one minute to repair and grind a drill bit, with high grinding efficiency.
  • 2). Our bit grinding machine has high precision and good processing quality .
  • 3). The life of the drill grinding machine is long and the auxiliary time is small.
  • 4). This machines have fast to feed speed and high processing efficiency.
  • 5). The machines have been reduced processing procedures and improved work efficiency.


  1. Solve more than 80% of processing problems

  • 1). With one machine can repair and grind drill bits (milling cutter) of various diameters.
  • 2). The quality of the grinding machine is good, and the precision of the drill bit is guaranteed.
  • 3). Drill bit grinder can improve the cutting performance of the tool and improve the machining efficiency.
  • 4). The machines have small cutting load and long tool’s life.
  • 5). The drill bit grinder can reduce the breaking edge of milling cutter and improve the service life of milling cutter.
  • 6). Our grinder machine can solve the problems of hole deviation, hole expansion, hole shrinkage and burr in general hole processing.
  • 7). Using our machines will solve the problems of short drill life, low drilling efficiency and difficult chip discharge caused by deep hole machining.


  1. Provide perfect after – sales service

  • 1). Provide customers with the most professional and economical purchasing plan fro free of charge.
  • 2). Help customers to check the machine platform for free, and develop special grinding tool’s SOP.
  • 3). Help customers improve the processing technology and improve the processing efficiency for free of charge.
  • 4). Provide customers with professional tool’s knowledge and advanced processing technology for free of charge.


How to grind the drill to be sharp and durable?

How to grind the drill to be sharp and durable?

How to grind the drill to be sharp and durable?

  1. Sharpen the chisel edge to be a little bit shorter, but it can’t be removed, reducing the feed resistance.
  2. Take advantage of the opportunity to shorten the chisel edge and try to improve the negative land angle at the chisel edge. Increase the land angle of this place can reduce the cutting force, make drilling light.
  3. Use the larger Lip Relief Angle. Reduce friction resistance and make drilling easy.
  4. Reduce the point angle. The proper reduction of point angle can increase the positive pressure of the cutting edge on the cutting surface, which is the same with the v-belt drive. But too small will affect the front angle of the cutting edge.
  5. The holes with less strict aperture and roughness can keep the slight imbalance between the two edges. In this way, the hole diameter at the orifice is slightly larger, which can reduce the friction between the blade belt and the orifice wall.

If you choose a drill bit grinder to repair and grind your bit, it will save you a lot of trouble. Fool operation, simple, a few minutes to complete the bit grinding work.

Tips for using drill bits

Although the drill is worn out, it can be repaired by a drill bit grinder. However, in ordinary use, different drill bits also have many tips. If you do not know how to use the drill bits, it will cause serious damage to the drill bit. It is impossible to use the drill bit grinding machine for repair, and the cost will also increase.

Operation Tips

There are some pointers that, when followed, will retain the life of the above drill types.

  • Hard materials need slow drilling speeds, and soft materials need faster drilling speeds. And as the hole deepens, the speed decreases. For the precise recommended drilling speed, the HSS drill can see the following formula.
  • You can drill holes first to allow for more accurate drilling.
  • Always make sure the drill is sharp to ensure less load on the power tool and better cutting effect.
  • If you plan to drill down to a piece of wood, use a wooden pad at the back of the job to prevent the material from breaking.
  • To achieve better drilling results, the cutting fluid is applied to the bit when drilling metal (except brass and iron).
  • Large bit will transfer a lot of reaction force to the drill bit, so be ready to stick with it.
  • All drill bits should be regularly removed from their flutes and airflow should be added around the drill to cool it.
  • Always apply pressure on a straight line with a drill. You should have enough to keep the bit together, but not too much, the tool’s motor gear or the bit deflected.
  • To prevent material breakouts, reduce the pressure you apply and get the drill through the last part of the hole.
  • Be sure to let the drill cool naturally. Don’t force them to cool in water (or any other liquid).

Operation instructions of drill bit grinder

PG drill bit grinder operational processes, Drill Re-sharpener, Drill Bit Grinding Machine Manufacturers, drill bit grinder, twist drill bits, drill bit

How to use drill bit grinder?

Grinding of Cutting Lip Angle

Start switch, after the motor turns steadily, place the fixture group of the chuck on the right side of the grinding table. Make the notch of the fixing seat is aligned to the stepped surface.

Push it to the end until after grinding sound has stopped, then take it out and turn 180 ° .  Grind the other side in the same way until silent.

Do not hold the drill handle while grinding, the force will affect the center of the drill uneven.

Cutting Lip Angle adjustable Angle 90 ° ~ 135 °


Grinding of Lip Clearance Angle

When grinding the dead center, chuck fixed group in the dead center grinding, gently pushed to the bottom of the grinding wheel, in the end, after spinning around by the end of silent, then take it out and turn 180 ° . Grind the other side in the same way until silent.

When the dead center is ground, the clamping head fixing tool set moves up and down. The position of the center of the missing Angle line of the clamping head fixator is aligned with the locating pin on the grinding seat.


Grinding of Major Cutting Lip

Grinding major cutting lip, chuck fixed with a group in the chisel edge grinding, gently push the bottom wheel, spin to the right to silence, then return to the center, take out and turn 180 °, grinding to the silent on the other side in the same way.

All contact holes in the machine must be cleaned immediately after the drill has been ground for the next use.

Glad Tidings: PURROS’s Universal Tool Grinder successfully entered the Kuwaiti market

Kuwait, officially the State of Kuwait is a country in Western Asia. Situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, it shares borders with Iraq and Saudi Arabia.

PURROS's Universal Tool Grinder 600F, buy drill bit grinder

PURROS’s Universal Tool Grinder 600F

Congratulations to PURROS Machinery Co., Ltd. that PG-600F Universal Tool Grinder to successfully enter the Kuwaiti market.
The success in Kuwait market, fully reflect powerful competitiveness of PURROS drill grinding machine in drill grinding industry of Kuwait, at the same time, it has also enhanced our brand awareness in the throughout Middle East.
Pursue higher quality to build more perfect products and continue to explore overseas markets, which is the responsibility and goals of the PURROS Machinery Co., Ltd. We will continuously improve product quality and better serve global customers. Thank you!

4 guidelines for how to precisely grind drill bits

4 guidelines for how to precisely grind drill bits, drill bit grinder

1. Correctly select grinding wheel (Including type and model)
2. For new drill bits or cutting tools, first step to check and record the main geometric parameters, especially record re-grinding situation of chamfering blade, chamfering, and chisel edge of drill bits or cutting tools.
3. Input the parameter data of grinding wheel, then input data of grinded drill bits or cutting tools.
4. To detect the main parameters of drill bits or cutting tools after grinding, and compare with grinding before, re-grinding again if there are different.

For more drill bit grinding guidelines, please feel free to contact drill bit grinding expert (PURROS).

Safety operation procedure for semi-automatic drill bit sharpening machine

Safety operation procedure for semi-automatic drill bit grinder

  1. The grinding wheel should be returned first, then the drill bit is mounted on the drill bit to adjust the Angle.
  2. When the drill bit turns normally, the machine meshes well and can be grinded. The protective cover should be complete and normal before grinding.
  3. Manual feed should be carried out slowly, especially when the grinding wheel is in contact with the drill bit.
  4. After the drill bit grinding is finished, exit the grinding tool and stop the lathe. The drill bit can be unloaded until it is stationary.
  5. After the drill bit is loaded, the wrench should be removed in time and not allowed on the chuck.
  6. When dressing the grinding wheel, put the feed handle in the neutral position, and after the grinding wheel turns normally, the it can be redressed. The fixture should be fastened, the feed should be slow; Wear protective glasses, the head should be avoided, the protective cover should be installed, the dust collection device should start. Replacement of new grinding wheel shall comply with the general safety regulations of the grinder.
  7. The workpiece should be put in place to prevent injuries.

Related articles: Top Safety Tips When Using a Drill Bit Grinder

PURROS drill bit grinder with best grinding wheel. Drill's Grinding Wheel, 4.5 grinding wheel, 3 grinding wheel, 4 grinding wheel, 6 grinding wheel, 7 grinding wheel, 8 grinding wheel

PURROS Drill bit grinder – Grinding wheel

  1. abrasive grain

The grinding wheel of different materials is suitable for grinding different kinds of cutting tools. Different parts of the tool need to be used in different sizes to ensure the best combination of blade protection and processing efficiency.

Alumina: used for grinding HSS drill bit. The grinding wheel is cheap and easy to be modified into different shapes for grinding complicated knives.

Silicon carbide: used to modify the CBN wheel and diamond wheel.

CBN (cubic boron carbide) : used for grinding HSS drill bit.

Diamond: used for grinding HM drill bit.

PURROS drill bit grinder with best grinding wheel. Drill's Grinding Wheel, 4.5 grinding wheel, 3 grinding wheel, 4 grinding wheel, 6 grinding wheel, 7 grinding wheel, 8 grinding wheel

PURROS drill bit grinder with best grinding wheel.
Drill’s Grinding Wheel, 4.5 grinding wheel, 3 grinding wheel, 4 grinding wheel, 6 grinding wheel, 7 grinding wheel, 8 grinding wheel

  1. Shape of grinding wheel

In order to facilitate the grinding of different parts of the tool, the grinding wheel should have different shapes. The most common ones are:

Parallel grinding wheel (1A1): grinding top Angle, outer diameter, back, etc.

Disc wheel (12V9,11V9): grinding spiral groove, the main of milling cutter, cutting edge, trimming blade, etc.

After a period of use, the grinding wheel needs to be modified (including plane, Angle and rounded Angle R). The grinding wheel must always be cleaned with the cleaning stone to clean up the chips to improve the grinding ability of the grinding wheel.

Drill bit geometry has several characteristics buy drill bit grinder

Why are twist drill bit especially easy to wear?

There are several disadvantages to the twist drill:

(1) the internal and external difference of the front Angle values of the points on the main Cutting Edge of standard twist drill is too large. The front Angle of the main cutting edge at the outer edge of the bit is about +30; The front Angle near the core is about -30.

Close to the front Angle of the drill center is too small, causing the chip to deform large, the cutting resistance is large; Near the outer edge of the anterior horn is too large, in processing hard materials, the strength of the cutting edge is often insufficient.

(2) the transverse edge is long, and the front Angle of the transverse edge is a large negative value, which is -5 4°~-6 0°, which will produce a large axial force.

(3) compared with other types of cutting tools, the main cutting edge of standard twist drill is very long, which is not good for cutting and cutting.

(4) take place after the deputy vice cutting edge of blade Angle is zero value, cause vice knife after the friction between the surface and hole wall, cutting temperature rise, the outer edge of the corner of bit wear is bigger, has processing surface roughness.Continue reading