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Technical Information · issue 13 of 2003

Square nylon line; STIHL TrimCut mowing heads; STI

IssueTI 13/2003

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TI 13/2003 page 1
STIH)

Technical Information

                                                                                            13.2003

  Cutting tools for STIHL brushcutters and clearing saws

  Contents
  1.
  2.
       Square nylon line
       STIHL TrimCut mowing heads
  3.   STIHL AUTOCUT 25-2, 30-2, 40-2 and 40-4 mowing heads
  4.   Storing nylon line
  5.   Blade on deflector

  6.   Universal sharpening template for brush knives
  7.   Documentation of spare parts for cutting tools

  1.    Square nylon line
                                                                  Design changes have been implemented in
                                                                  some mowing heads to permit use of the

                                                                  square nylon line. These changes are summarized
                                                                  in sections 2 and 3 of this Technical Information.

                                                                  Square line yields the following advantages,
                                                                  depending on the conditions of use of the nylon line,
                                                                  such as the nature of the material to be cut, use of

                                                                  the mowing head and machine:
                                                                  .   Cut result increased by up to 10 %
                                                    681TI039 KN

                                                                  .   Service life extended by up to 10 %
                                                                  .   Compared with the standard round mowing line,
  Cross-sections of STIHL nylon line                                  square line produces a subjectively more
  Left: Round mowing line                                             "aggressive" cutting sound and a sound
  Middle: Round "quiet" mowing line                                   pressure level comparable to that of the round
  Right: Square version                                               quiet line.
  Nylon line with a square cross-section has been
  available for some time along with the range of
  round and round quiet lines.

  TI_13_2003_03_01_01.fm                                                                                english / USA
)m~ge 2                                                                     Technical Information 13.2003

1.1   Principle of operation                            The specified designation 0.095“ for square line
                                                        consequently represents neither the width nor the
                                                        diagonal measurement. It merely serves as a code
                                                        value indicating that it has a similar cross sectional
                                                        area as that of 0.095“ diameter round line.

                                                        Correlation of dimensions
                                                        Code value /      Actual Width
                                                        dimension         (values rounded)
                                                        [in]              [in]
                                681TI040 KN

                                                        0.095             0.083

                                                        0.105             0.095
All types of mowing line wear down at the outer end.
A sectional view of the square line shows that one

edge points in the direction of movement.               1.3    Use
Compared with a round line with the same sectional
area, the square line displays a higher resistance to

                                                        1.3.1 Modified mowing heads
air (more “drag“) in this position.
                                                        The square mowing lines can be used in the latest
This results in a slightly lower working speed of the   versions of the following mowing heads:
machine as compared with round line. This in turn
leads to slightly lower engine noise.
                                                        –
                                                              STIHL TrimCut 30-2, TrimCut 40-2
                                                              and TrimCut 50-2
                                                        –     STIHL AUTOCUT 25-2, AUTOCUT 30-2,
                                                              AUTOCUT 40-2 and AUTOCUT 40-4
1.2   Dimensions and symbol

A new symbol has been introduced to identify the        Further details can be found in sections 2 and 3 of
dimensions of the square line:                          this Technical Information.

                                                        1.3.2 Unchanged mowing heads
         = Square mowing line
                                                        The automatic line advance systems of the STIHL

                                                        SuperCut mowing heads are designed exclusively
Round and square lines with the same designation        for the use of round mowing line.
also have the same sectional area!
                                                        Only round mowing line can be used in older

For example:                                            versions of STIHL AUTOCUT mowing heads with
A square mowing line with 0.095“ designation has        unmodified spools (see section 3).

the same cross sectional area as the round version
with 0.095“ diameter (symbol Ø).

                                                                                        TI_13_2003_03_01_01.fm

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TI 13/2003 page 2
Technical Information 13.2003                                                                                 Page 3

2.     STIHL TrimCut mowing heads                                2.2   Spool

                                                                                                                     681TI041 KN
                                                                 New openings for threading in the mowing line
                1         2                                      Left: Previous version

                                                                 Right: New version

                                                                 The same spool is used for all three versions

                                                   681TI048 KN

                                                                 of the TrimCut mowing head. The new spool
                                                                 4002 713 3016 can be identified by the specially
Only the modified version of the STIHL TrimCut
mowing heads (1) will be supplied in the future. The
                                                                 shaped openings for threading in the line.
                                                                 The new spool can be filled with round or square
previous spool (2) will be replaced by a new version.            mowing line with dimensions from 0.095“ to 0.130“.
                                                                 Use the quantities recommended in section 2.4
Despite these changes, the part numbers for the
                                                                 "Quantities" for the respective mowing heads.
mowing heads will remain unchanged.

2.1    Reasons for the change
.     Use of round lines of different diameter                   2.3   Interchangeability

                                                                 The advantages of the modified mowing heads can
.     Use of square lines of different thickness
                                                                 also be had with the previous mowing heads,

These changes meet with customers' requests for                  provided that the previous spool is replaced by the
mowing heads which can be used with mowing lines                 new version 4002 713 3016.
of different types and thickness.

                                                                 2.4   Quantities

                                                                 The following tables list the recommended values
                                                                 for mowing line as a function of the mowing head.
                                                                 These recommendations should be observed.

                                                                 Basic rule: the greater the size of the mowing line,
                                                                 the more power must be output by the machine in

                                                                 order to obtain reasonable performance.

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)m~ge 4                                                                          Technical Information 13.2003

STIHL TrimCut 30-2                                        STIHL TrimCut 50-2
0.095“                     0.105“                          0.105“                      0.130“
16 ft                      12 ft                           12 ft                       6 ft
Standard filling                                           Standard filling

STIHL TrimCut 40-2
0.095“                     0.105“
16 ft                      12 ft
                           Standard filling

2.5    Instruction sheet

The instruction sheet supplied with the mowing
heads has also been edited with the introduction of
the new spool.

2.6    Summary                                                    fo
Item     Part name                                 Previous                   New                  Remarks
 1       STIHL TrimCut 30-2 mowing head            4002 710 2193              4002 710 2193        1)
 2       STIHL TrimCut 40-2 mowing head            4003 710 2193              4003 710 2193        1)

 3       STIHL TrimCut 50-2 mowing head            4005 710 2193              4005 710 2193        1)
         including Item 4 in each case:

 4       Spool                                     4002 713 3001              4002 713 3016        2)

         Other parts as before
Modification to be introduced continuously

Remarks
1) Unmodified version of part will continue to be supplied while stocks last
2) Previous version of part only remains available while stocks last

                                                                                          TI_13_2003_03_01_01.fm

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TI 13/2003 page 3
Technical Information 13.2003                                                                                  Page 5

3.    STIHL AUTOCUT 25-2, 30-2, 40-2                              3.1   Reasons for the changes
      and 40-4 mowing heads                                       The reasons for the changes are the same as for the
                                                                  STIHL TrimCut mowing heads, see section 2.1 of
                                                                  this Technical Information.
                             5

                         1                                        3.2   Spool




                                                                                                                      681TI043 KN
                         3
                                                    681TI042 KN

                                                                  Changed openings for threading in the mowing line

Example: Exploded drawing of the
                                                                  on AUTOCUT 25-2
                                                                  Left: Previous version
STIHL AUTOCUT 25-2 mowing head                                    Right: New version

The modified versions of the STIHL                                The new spools can be identified by the specially

AUTOCUT 25-2 (1), AUTOCUT 30-2 (2),                               shaped openings for threading in the mowing line.
AUTOCUT 40-2 (2) and AUTOCUT 40-4 (3)
                                                                  The new spools can be filled with round or square
mowing heads will be supplied in the future.
                                                                  mowing line with dimensions of 0.095“ and 0.105“

The previous versions of the spool (4) and                        depending on the mowing head version. The

sleeve/eyelet (5) will be replaced by new versions.               quantities recommended in section 3.5 "Quantities"
Together with the changeover to the new spools, the               should be used for each mowing head.
STIHL AUTOCUT 30-2 and 40-4 mowing heads will                     The part numbers of the new spools are listed in the

be filled with a round mowing line with 0.105“                    Summary.
diameter. A round mowing line with 0.095“ diameter
was used to date for the standard filling. This

change brings these mowing heads into line with the
more powerful brushcutters and clearing saws.
Consequences of changing the standard filling:

.    STIHL AUTOCUT 40-4: a new spool with 0.105“
     mowing line will be used instead of the previous

     version with 0.095“ mowing line.
.    STIHL AUTOCUT 30-2: the previous, wound
     spool (0.095“ mowing line) will no longer be
     used when supplying spare parts. Only the
     version used with the AUTOCUT 40-2 (0.105“
     mowing line) will be supplied instead.
The part numbers for these mowing heads will
remain unchanged.

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)m~ge 6                                                                                  Technical Information 13.2003

3.3    Sleeve/Eyelet                                               Basic rule: the greater the size of the mowing line,
                                                                   the more power must be output by the machine in
          2,8 mm                 3,1 mm                            order to obtain reasonable performance.
         (0.110")                (0.122")
                                                                   STIHL AUTOCUT 25-2
                                                                   0.095“                      0.105“
                                                                   32 ft                       22 ft
                                                                   Standard filling

                                                    681TI044 KN

                                                                   STIHL AUTOCUT 30-2

                                                                   0.095“                      0.105“
Slot width of the sleeve/eyelet
Left: Previous version 4003 713 8300                               50 ft                       40 ft

Right: New version 4003 713 8301                                                               Standard filling

The same sleeve/eyelet is used for all modified

versions of the AUTOCUT mowing heads. The new                      STIHL AUTOCUT 40-2
sleeve/eyelet 4003 713 8301 can be identified by
                                                                   0.105“                      0.120“
the slightly wider slot.
                                                                   40 ft
                                                                             fo                30 ft
                                                                   Standard filling
3.4    Interchangeability
The advantages of the modified mowing heads can                    STIHL AUTOCUT 40-4

also be had with the previous mowing heads,
                                                                   0.095“                      0.105“
provided that the previous spool is replaced by the
new version.                                                       36 ft                       28 ft
                                                                                               Standard filling

3.5    Quantities
The following tables list the recommended values                   3.6   Instruction sheet
for mowing line as a function of the mowing head.                  The instruction sheet supplied with the mowing

These recommendations should be observed.                          heads has also been edited with introduction of the
                                                                   new spool.

3.7    Summary

Item     Part name                                          Previous                  New                   Remarks

 1       STIHL AUTOCUT 25-2 mowing head;                     4002 710 2191            4002 710 2191         1)
         including Items 2 and 9:
 2       Spool with line; including item 3:                  4002 710 4313            4002 710 4313         2)
 3       Spool (without line)                                4002 713 3008            4002 713 3017         2)

 4       STIHL AUTOCUT 30-2 mowing head;                     4002 710 2187            4002 710 2187         1)
         including Items 5 and 9:
 5       Spool with line;                                    4002 710 4311            4003 710 4303         2)
         including Item 6:
 6       Spool (without line)                                4003 713 3005            4003 713 3011         2)

                                                                                                  TI_13_2003_03_01_01.fm

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Technical Information 13.2003                                                                                  Page 7

Item         Part name                                    Previous                New                     Remarks
    7        STIHL AUTOCUT 40-2 mowing head;              4003 710 2189           4003 710 2189           1)
             including Items 8 and 9:
    8        Spool with line;                             4003 710 4303           4003 710 4303           2)
             including Item 6:
    9        Sleeve/Eyelet (2x)                           4003 713 8300           4003 713 8301           2)

10           STIHL AUTOCUT 40-4 mowing head;;             4005 710 2102           4005 710 2102           1)
             including Items 11 and 13:
11           Spool with line;                             4003 710 4302           4003 710 4305           2)

             including Item 12:

12           Spool (without line)                         4003 713 3010           4003 713 3012           2)
13           Sleeve/Eyelet (4x)                           4003 713 8300           4003 713 8301           2)

             Other parts as before

Modification to be introduced continuously
Remarks
1) Unmodified version of part will continue to be supplied while stocks last
2) Previous version of part only remains available while stocks last

4.        Storing nylon line                                    5.       Blade on deflector

The durability of the mowing line can degrade after
prolonged storage. The following points should

therefore be observed:
.       Mowing line or filled spools should not be stored
        for long periods in hot environments (e.g. inside

                                                                                                    1
        vehicles, enclosed trailers, etc.).
                                                                              1
.       Mowing line must not be exposed to direct

        sunlight for long periods of time (e.g. displays in
        a storefront window).
                                                                                                                      681TI045 KN

These points also apply for the blades of the

                                                                     2                               2
STIHL PolyCut mowing heads.
                                                                To optimize the cutting performance of the mowing

                                                                line, the line limiter (1) on the deflector (2) must be
                                                                sharp and free from dirt or scraps. The line limiter
                                                                must be examined at regular intervals and replaced
                                                                if blunt.

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)m~ge 8                                                                                 Technical Information 13.2003

6.     Universal sharpening template for                           7.    Documentation of spare parts for
       brush knives                                                      cutting tools
                                                                   In the future, cutting tools and their spare parts will
              1                                                    be listed in the "FS Cutting Tools Catalog" and no
                                                                   longer in spare parts lists for the machines.



                      25,4 mm                 3
                        (1")
              1

                                        2
                                              3
                                                     681TI047 KN

                       20 mm
                      (0.787")
The metal sharpening template 4020 890 5500 (1)
is used as follows:

.    Secure the centering disc (2) so that the
     1“/25.4 mm collar rests against the template.

.    Insert the centering plate (2) in the bore of the
     brush knife (3) as illustrated. This applies for
     both the bore with 0.787“ (20 mm) and the bore

     with 1“ (25.4 mm) diameter!

Last Technical Information on STIHL cutting tools: TI 55.2001

© ANDREAS STIHL AG & Co. KG, 2003                                  Technical Documentation
                                                                   D1/MTK-na                                         7919

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