GRAFS GR – automatic heavy-duty machine for grinding straight industrial blades

GRAFS GR grinding machine is designed for sharpening knives used in printing, paper, metal processing, wood and recycling industry. The knife sharpening machine model GRAFS GR can be supplied in 4 different grinding lengths: mm 1.200, mm 1.800, mm 2.100 and mm 2.400.
The grinder has a number of improvements to achieve high-quality sharpening for many years of use. It is equipped with a rotating electromagnetic chuck, it is also possible to attach knives using special clamps on the other side of the table. Angle from 0 to 90 degrees.
Proper cooling of the sharpened surfaces is ensured by a cooling system with a tank and magnetic coolant cleaner with rotating discs – model MS60 or paper filter PS (as an option).
Developed in our firm the special holding segment allows for quick and easy removal and fastening of the grinding wheel with three clamping screws.
The carriage is equipped with the best class rolling rollers (PWTR) which ensures quiet and smooth operation.
In addition, as standard, the grinder is equipped with a slide carriage speed control
system (potentiometer and inverter). Also model GR is equipped in Programmable
Logic Controller (PLC) and HMI 7,0″ touch screen control panel (in standard price).
The machine is perfect for sharpening special purpose knives, where high precision grinding and rigidity are needed, e.g. guillotine knives for cutting paper. It is suitable also for chipper knives, granulator blades, veneer knives.
The machine is equipped with a standard corundum grinding wheel for sharpening knives with an NC, SS steel insert.
The machine has all necessary electrical tests and CE DECLARATION, build in Poland on European components.

Easy of use 7" HMI Touch panel mounting on grinding carriage and PLC controller
Fast grinding wheel motor up and down movement - for grinding wheel changing
Easy grinding wheel assembly (a special holder developed in our company enables quick assembly of the grinding wheel with 3 clamping screws)
Efficient sharpening of both mild steel and increased hardness such as: NC11LV, HSS, HM carbides (it is recommended to attach a paper separator PS for carbides grinding)
External tank with pump for coolant,
Solid welded construction without any vibrations during work
The whole carriage can be moved relative to the trolley, thanks to this function we can sharpen / grind wider objects. e.g. knives up to 350 mm wide!
Appropriate grinding wheel motor bearings
Adjustment of carriage speed from 1 to 16 m/min (using the potentiometer)
Automatic grinding - feed adjustable during operation (from 0.001 mm for two passes), automatic sparking out after the grinding process
Machine is equipped as standard with the highest quality corundum grinding wheel
We provide training in the operation of the machine and material advice
The machine is adapted to individual customer needs
Max grinding lenght
1200 mm,1800 mm, 2000 mm, 2400 mm
Max grinding width*
200 mm
Grinding wheel motor speed
1450 rpm (switched right/left)
Carriage speed
1m/min - 16m/min (smooth regulation)
Grinding motor power
3.5 kW, 4 kW, 5.5 kW, 7.5 kW, 11 kW
400 V – 50 Hz – 3 f
Coolant filter efficiency
60 L/min
Coolant tank cappacity
150 L (up to 300 L - upon request)
Grinding wheel (every type: corundum, CBN, DIA, Grinding wheel with segments)
⌀ 180 - 250 mm
Grinding motor swivel
+ / - 10 °
Manual clamping magnet (permanent)
3 units 150 x 600 mm (90N/cm2)
Swivel range magnet
+ / - 120 ° (Polarity 20 mm)
The machine is built in accordance to: EN 60 204-1 Norms. EC Norms 89/392.
*The grinding width range can be increased due to the carriage advance function relative to troley.
CBN Grinding wheel ⌀ 250 mm
Grinding wheel with insert made of HSS, NC10, NC11 (adapted to the customer's needs).
Diamond Grinding wheel ⌀ 200 mm
Grinding wheel for sharpening knives with carbide insert HM (adjusted to the customer's needs).
Grinding wheel with corundum segments ⌀ 250 mm
Grinding wheel for more efficient sharpening of knives, where a quick material removal is required (e.g. knives for mills, crushers, chipper knives). We adapt the grinding wheel to the customer's needs.
Specialist full-day training (STEEL SS, NC, HSS) at the customer's premises.
Training in the field of professional knife sharpening, (the price does not include travel costs).



Transparent functions on the panel allow for easy and efficient operation of the machine.

The carriage speed is set by the potentiometer knob. The position of the grinding wheel relative to the surface is indicated by the scale, the number of passes are displayed on the panel.

Model GRAFS GR is equipped with HMI 7 “touch panel and PLC as standard.


GRAFS GR can be equipped in the swiveling electromagnetic chuck and / or with T channel plate on the other side of the chuck (for clamps mounting).
These two systems allows for secure fastening of the workpiece and precise grinding angle setting in the range from 0 to 90 degrees.


The machine is equipped with an inverter for regulating the carriage speed from 1 to 16 m / min., and HMI 7″ touch panel and digital Controller (PLC).
All electronic components are high-quality materials from proven manufacturers (Schneider mainly).

Machine functions:
– automatic grinding (programmed at the beginning or during operation)
– automatic sparking out,
– pause mode,
– infeed from 0.001 mm to 0.03 mm, the number of carriage passes freely changed during each operation.


Specially designed holder allows for mounting different types of grinding wheels: ringwheels, segmental heads, diamond and CBN wheels (diameter from 150 mm up to 250 mm).


The grinder has covers to prevent excessive release of coolant dust during grinding.

The amount of coolant fed to the machine by pump can be freely adjusted.

The whole carriage can be manually positioned over the workpiece, which prevents the abrasive wheel from accidential hitting the workpiece.

Machine has fast drive of main motor up / down by stepper motor, and slow approach by hand wheel. Steering by hand wheel can be also possible during work of the machine.
The electromagnetic table has polarity from 5mm up to 25 mm (depends from order) and with max force 120N/cm2. Chuck is easily controlled from the control panel.


The machine’s grinding wheel motor is manufactured in one of the oldest polish company: CELMA Inducta.
Motor is specially reinforced by GRAFS and is equipped with special reinforced bearings with the elimination of axial play.
In GR model motor is available in several power variants: 4 kW, 5.5 kW, 7.5 kW, 11 kW.
The main motor slide is precisely adjustable and runs on bronze guides.


The machining coolant filtration module developed and built in our company consists of a magnetic separator with rotating neodymium magnets (for removing magnetic spoil) and a paper separator  – fig. next to it (for removing non-magnetic spoil, e.g. dust from abrasive of grinding wheel).

The combination of both filters gives a high level of coolant purity which translates into quality and speed of sharpening process.




The machine support can be manually positioned over the knife, which allows for secure positioning of the grinding wheel disc relative to the workpiece.

Thanks to the possibility of sliding the carriage relative to the troley, it is also possible to sharpen / grind objects of larger widths (up to 350 mm).


Constructed of welded steel plates with a thickness of 20 mm. The trolley moves on 4 PWTR rollers with a diameter of 62mm (including 1 on an adjustable eccentric) for precise adjustment of the position of the rollers in relation to the guides. Additionally, on one of the guides, 2 internal fixed rollers and 2 external adjustable rollers are used to guide the trolley evenly in relation to the base.


The machine base is made of electrowelded steel sheets with appropriate ribs, which makes the whole structure extremely stable. The rigid structure helps to avoid any vibrations or deflections during machining.

The base is available in several lengths enabling the grinding range: 1200 mm, 1800 mm, 2000 mm, 2400 mm.

As a carriage running system, there are two steel guides equipped with hardened straps of appropriate hardness. High-strength PWTR rollers move on the straps. This solution is more durable than standard linear systems used in CNC machines.