Solid belt supports0 pages

SANDVIK PROCESS SYSTEMS

Product information

Steel belt support
Steel belt support 01.2014

Cast iron skid bars CP61

Belts in conveyors running in hot environments
such as bake ovens are often supported by cast
iron skid bars. These are made of a special kind of
cast iron that can stand the wear from the steel
belt without harming the steel surface.

Placing

To ensure the best working conditions Sandvik recommends that
at least 10 % of the belt supports are graphite bars (see Product
Information sheet CP60-ENG). The graphite will lubricate the steel
belt during operation.

The brackets have long holes in each end for mounting on a
conveyor structure. For belts wider than 800 mm two cast iron
skid bars have to be mounted on the same bracket. For belt width
larger than 1 500 mm, more than one combination of cast iron
skid bars are possible.

Scope of supply
Cast iron skid bars are available in three lengths: 460, 560 and 710
mm. Each cast iron skid bar has mounting holes suitable for M8
screws symmetrically placed.

L=710
L=560

L=460
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The length of the cast iron skid bar support should be slightly
narrower than the belt, measured perpendicular to the running
direction of the belt. The general rule is:
Support length = Belt width – 75 to 100 mm

The distance between the supports depend on the permissible
belt sag and the maximum allowed pressure on the cast iron skid
bar. Normally the distance is about 0.8 up to 1.0 m. the surface
pressure must not exceed 0.5 N/cm² (0.005 MPa).
The cast iron skid bars should be given a coat of graphite when
first mounted in conveyors with a solid steel belt.

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8

Material properties
It’s recommended that the finished sliding surface of the skid bar
has a microstructure consisting of a pearlitic matrix with evenly
spread type A graphite flakes acc. to ASTM A247 with no hard
particles (see photo).

There is an option to also get the support beam for the cast iron
skid bars from Sandvik. The beam or bracket is available in four
lengths for each standard belt width. The screws for mounting the
cast iron skid bar are included in the bracket.

Microstructure consisting of a pearlite matrix and
a type A graphite flakes.

Support bracket

Cast iron skid bar

The same bracket is used for graphite bar supports.

Maximum allowed amount of ferrite is 10%. No ledeburite is
allowed.
The recommended composition to achieve the right structure in
the cast skids is:
C %:t
Si %:t
Mn %t

3.1 – 3.4t
1.6 – 2.1t
0.6 – 0.8t

P %:t
S %:t
Ceqv %:t

< 0.05
0.05 – 0.15
3.6 – 3.9