STIHL harvester chains are precision made in STIHL’s
Switzerland based factories. These chains are produced
on special machinery custom designed and built by
STIHL. STIHL has determined the ideal material mix for
every component of the chain. Meticulous production
processes and strict quality controls combined with
proper chain maintenance ensure less friction for smooth
operation and a long wear life.
This STIHL Harvester Chain Manual was created for and
is provided to STIHL Dealers and owners/operators of
harvester equipment utilizing STIHL chain in the cutting
attachment. This manual provides information, that when
followed, results in a properly sharpened and well
maintained harvester chain. Good cutting performance,
positively contributes to the service life of the cutting
attachment. However, the design and power of the drive
unit, the quality/condition of the harvester guide bar along
with working technique are also factors impacting
harvester performance.
STIHL OILOMATIC® System of Chain
Lubrication
Chain lubrication has a decisive influence on the service
life of a chain.
The patented OILOMATIC® principle of chain lubrication
extends the useful life of the chain, guide bar and chain
sprocket. Unlike conventional chains, each drive link of
STIHL OILOMATIC
channel which is angled upwards and backwards.
®
saw chain incorporates an oil
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2. Safety Precautions and General Information
2.1 Safety Precautions for working with
mechanical timber harvesting
machines
Saw chain breakage and thrown parts of chain, called
"chain shot" (chain shot is the term commonly used by
manufacturers as well as forestry professionals to
describe the parts of the chain that are thrown through
the air when a chain breaks).
These harvester machines impose a very heavy load on
the cutting attachment. For this reason it is necessary to
observe the notes and instructions on reducing the risk of
chain breakage and possible injury.
It is important you read and understand the instruction
manual before using your machine for the first time and
keep it in a safe place for future reference. Nonobservance of the safety precautions may result in
serious or even fatal injury.
Observe all applicable safety regulations, standards and
ordinances.
The following information is intended to supplement the
machine-specific instruction manual, but not replace it:
Position the guide bar and chain so that parts are not
thrown in the direction of the operator.
The timber harvester's cab should be equipped with
appropriate safety windows.
A chain speed of 40 m/s (131.23 ft./sec.) must not be
exceeded when using STIHL RAPID
Harvester saw chains (RMH, RMHS).
The area around the chain sprocket must be fitted
with a suitable guard.
Make sure that bystanders keep a minimum distance
of 70 m (230 ft.) from the harvester when it is in
cutting operations.
Inspect the chain regularly for damage – do not
continue working with a damaged chain – replace a
damaged chain or replace chipped cutters and other
damaged parts of the chain.
STIHL recommends the use of original STIHL
replacement parts for repairs – do not install used
parts. Repairing the chain with used or non-OEM parts
could cause a premature failure resulting in severe
injury or death and possible damage to the machine
components.
™
Micro™
STIHL recommends that the complete saw chain
must be replaced after it has broken twice.
Always resharpen STIHL chains to factory
specifications.
Make sure the chain is always properly tensioned.
Replace the chain sprocket as soon as it shows any
visible signs of wear. A specific wear depth that can
be measuered to 0.6 mm (0.025 in.) indicates that the
sprocket needs replacement. It is recommended that
a sprocket should be replaced after the use of 10
chains.
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2. Safety Precautions and General Information
When the chain is running, no persons may stand at
the same level as the guide bar.
™
STIHL RAPID
for use on timber harvesters only. They must not be
used on handheld chain saws or for any other
purpose.
The components of the cutting attachment must
match, i.e. chain pitch and drive link gauge.
STIHL recommends that chain links, chain drivers and
chain cutters be inspected for cracks and other
damage before the chain is placed into use, before
maintenance procedures such as sharpening or repair
are initiated.
STIHL recommends that machine operators check
with a labor or industries representative (i.e. OSHA)
and/or timber harvesting machine manufacturer in
regards to required guarding and appropriate
windshield thickness on harvesting machinery using
chain.
Micro™ Harvester chains are approved
2.2 General information
The guide bar and chain must always be well
lubricated at the proper oil flow rate. STIHL
recommends the use of STIHL Bar & Chain Oil or a
comparable quality bar and chain oil. In colder
temperatures use a STIHL "Winter" Grade Bar & Chain
oil or a comparable quality winter grade oil of another
manufacturer. Never use hydraulic oils for lubrication
of the chain and guide bar.
2.3 Before using for the first time –
changeover from other saw chains to
™
the STIHL RAPID
Micro™ Harvester
Special (RMHS)
The .404" RMHS chain has wide running faces to reduce
the load on the chain, guide bar and sprocket.
In order to utilize the benefits of the chain's wide running
faces and thus extend service life, it is necessary to check
that the widths of the running faces on the chain, guide
bar rails and chain sprocket match.
Higher chain speeds result in increased wear which
negatively impacts service life of the chain and bar and
increases the potential for chain breakage and
possible injury. Always monitor the factors that
influence chain performance. Influencing performance
factors such as feed force, chain speed, chain
sharpness, sprocket condition and guide bar integrity.
A chain speed of 40 m/s (131.23 ft./sec.) should not
be exceeded when using STIHL Harvester Chain.
Narrower saw chains cause a narrower wear pattern on
the guide bar and chain sprocket. If the new .404" RMHS
chain is mounted on a bar worn in such a way, the edge
pressure will be increased. This would result in excessive
wear or damage on the new chain.
It is recommended that a new chain sprocket and a new
guide bar be installed with the new chain to ensure
optimum break-in and operation.
Instead of a new guide bar, the rails of a used guide bar
can be deburred.
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3. STIHL Harvester Saw Chain
A harvester chain is subjected to extremely high loads
during operation. The individual parts of the chain are
exposed to constantly alternating tensile forces which
can result in cracks and finally cause the chain to break.
™
The STIHL RAPID
™
RAPID
specifically developed to withstand the continuous high
loads imposed in highly mechanized timber harvesting
operations. All parts of the chain have been strengthened
to greatly minimize the risk of cracks, while maintaining
the same high cutting capacity.
Micro™ Harvester Special (RMHS) have been
Micro™ Harvester (RMH) and STIHL
STIHL RAPID™ Micro™ Harvester (RMH)
STIHL harvester chains are designed for professional
applications under the toughest of operating conditions.
STIHL harvester chains are available in two versions:
STIHL RAPID
RAPID
™
™
Micro™ Harvester (RMH) and STIHL
Micro™ Harvester Special (RMHS).
Cutters
Semi-chisel chain with slim, straight-sided cutter. The
narrow cutter shape reduces cutting resistance. Depth
gauge setting is 1.5 mm (0.059 in.).
Tie straps and drive links
The reinforced tie straps, drive links and rivets are rated
to take account of the high driving power of harvesters
and the resultant high loads imposed on the chain.
Reduced distance between tie straps increases flexural
strength and reduces the risk of chain breakage.
STIHL RAPID™ Micro™ Harvester Special (RMHS)
Identification
Each cutter is marked with "H" just below the depth
gauge.
Cutters
Semi-chisel chain with slim, straight-sided cutter. The
offset depth gauge makes this a smooth running chain.
As a result, the risk of chain breakage is greatly reduced
and service life is extended. Depth gauge setting is
1.0 mm (0.039 in.).
Sliding surface has been
increased by patented,
asymmetric shape of toe
and heel. This results in
considerably reduced
pressure on the cutters for
a longer wear life.
Identification
Each cutter is marked with "HS" just below the depth
gauge.
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Tie straps
RMHSRMH
Drive links
3. STIHL Harvester Saw Chain
40 RMH:
Symmetrically shaped running faces. The tie straps are
non-directional.
40 RMHS:
Wear surface is increased by asymmetrically shaped
running faces. This greatly reduces the pressure on the
tie straps and prolongs the service life of the chain. Owing
to the different sizes of the running faces, the tie straps
are directional, i.e. there are left-hand and right-hand tie
straps.
The drive links are reinforced in the area of the rivet holes.
The part of the drive link that runs in the bar groove, the
tang, is stepped – 2.0 mm (0.080 in.) drive link gauge.
Reduced stress
All heavily stressed parts of the STIHL RMHS have been
specially strengthened. This means that the forces acting
on the drive links, tie straps, cutters and rivets can be
better spread over the whole chain. The strengthened
STIHL RAPID
therefore has an up to 70 % longer service life than
conventional harvester chains with a 2.0 mm (0.080 in.)
drive link gauge.
™
Micro™ Harvester Special (RMHS)
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3. STIHL Harvester Saw Chain
3.1 Specifications
Saw ChainRapid Harvester MicroRapid Harvester Special