The specialist unit R-Flex

Jun 26, 2019

Whether it be in the home or in industry - elastic abrasives in the R-Flex series from Klingspor are ideal for the fine grinding of various types of metal surfaces.

         Ein Marmorierkörper von Klingspor  gestaltet eine Edelstahloberfläche mit  Pfauenaugenmuster.

Whether it be in the home or in industry - elastic abrasives in the  R-Flex series from Klingspor are ideal for the fine grinding of various types of metal surfaces. 

When it comes to fine grinding or a thorough yet gentle cleaning of surfaces, elastic abrasives from Klingspor are the materials of choice. Unremarkable from the outside, they are normally found more in the second row. But that's just their guise; when put to use, the R-Flex products reveal their true qualities, like a special unit. The jack-ofall-trades can turn their hand to any job. In the home, they refresh old suede shoes and bring a shine to burnt iron soleplates, rusted ice skate runners and limescale- tarnished stainless steel sinks. In industrial applications, they provide the finishing touch to surgical instruments, aircraft and car parts, fountain pen nibs and food containers. The R-Flex products have been firm favourites in the Klingspor range since the late 1950s. They began with the mounted points. A short time later, the Schleiffix handblock conquered the market. This looks like an oversized eraser and was developed to remove small areas of damage and dirt from surfaces without damaging the material. Hartwig Dangendorf, Product Manager at Klingspor, reveals where the R-Flex name comes from. “R stands for rubber.  Although this isn't really rubber. It's usually a polyurethane compound. And Flex is an abbreviation for flexible. So it's an elastic mounted, flexible abrasive.”

Elastic all-rounder

The elasticity is the actual secret to the especially fine finish. “The elastic bonding makes the grain more flexible, allowing it to deviate backwards. This means that the abrasive does not penetrate the material, but instead simply scrapes over its surface,” explains Hartwig Dangendorf. Three factors influence the overall outcome: the bonding type, the bonding hardness and the grinding grain. “We currently offer R-Flex products in three bonding hardnesses: soft, medium or hard. The harder the bonding the more aggressive the abrasive, and the softer the bonding, the better the polishing effect. Ultimately, the requirements in relation to a handblock are naturally very different to those relating to a mechanically used SFM 656 mottling point”, adds Dangendorf. What the SFM 656 is known for, and what Klingspor can look back on as a particularly successful part of its history, is something that everyone has already seen at some point: on the surface of bistro tables in pavement cafés or on the tanker trucks on the motorway. “Peacock's eye” is the name of the special effect that is created mechanically with the help of the mottling point.  

Also made to measure

In addition to common dimensions and bonding hardnesses, Klingspor also offers its clients a service whereby elastic abrasives can be custom-made. For one client from the furniture industry, especially large steel rollers are coated in Haiger with R-Flex material - they are 1.3 metres long and have a diameter of 25 centimetres. Very small R-Flex strips are used, on the other hand, for a manufacturer of model railways. The fine brass rails on which the miniature trains run are polished to a shine with them. Hartwig Dangendorf specifically points out a particular feature of the handling of elastic abrasives used in mechanical applications: “The user should take care to ensure that the operating speed is not set too high. Essentially, the softer the bonding, the lower the operating speed. If the speed is too high, the R-Flex products will not function correctly. They start to smear and the grinding pattern becomes blurred.”


SFM 656
The mottling point is used mechanically to produce an even grinding pattern and creates special surface effects. The SFT 656 is especially used for the processing of stainless steel.


SFK 655
The small, elastic handblock is water-resistant and cleans metal, glass or plastic. The elastomer bonding plus silicon carbide grain makes the SFK 655 especially long-lasting.