Nisula 425H

Ideal weight/efficiency ratio for thinning

Nisula 425H is a thinning harvester head equipped with additional knives. The harvester head processes the stem in a controlled manner. A new type of head control improves the speed and precision of the process.
The new stronger drive motors increase the feeding capacity by 20% compared with the previous model. The new machined front knives provide improved delimbing efficiency and durability. The additional knives of the new 425H head increase productivity with even larger stems, something that harvester heads in the same weight category are not able to achieve. The additional knives also allow a larger delimbing diameter. The head is a most suitable choice for thinning.


Delimbed energy wood processing


Light harvesters
Farm tractors equipped with an adapter sleeve mounted crane
Light forwarders with head change facility
Lighter than 12-ton excavators


NCU3Lite with length and diameter measurement function
NCU3 with length and diameter measurement function + cubic volume measurement function
NCU3i with length and diameter measurement function + cubic volume measurement function + priority bucking function
NCU3X with length and diameter measurement function + cubic volume measurement function + value bucking function + data transfer facility
Compatibility with Motomit control systems


Saw control
Automatic chain adjuster
Colour marking
Stump treatment facility
Separate chain lubrication function

Technical data

Weight 410kg 904lb
Clean delimbing Ø 320mm 12.6"
Single cut Ø (1 stem) 425mm 16.8"
Number of delimbing knives 4 + 1 4 + 1
Opening of front knives 430mm 17"
Opening of additional knives 580mm 22.8"
Width in delimbing position (open/closed) 1100/940mm 43/37"
Height in delimbing position 880mm 34.6"
Height in felling position 880mm 34,6"
Operating pressure 210bar 3046psi
Required oil flow 120-150l/m 32-40gpm

Details 425H


The head is extremely easy to maintain. All the grease points can be handled with the head in one position.


The cylinders of the head do not move lengthways, which minimises the movements of the hoses and thereby the risk of damage.


The saw control system and the automatic chain adjuster available as accessories enhance cutting efficiency and usability and decrease chain/saw bar costs.


The additional knives located in the centre of the head and below the stem provide an exceptional triangular support for the stem while it is being handled. Thanks to this property, also extra-large stems are kept in a tight grip.


The triangular support structure facilitates and speeds up the handling of the stem and improves measurement accuracy.


The additional knives next to the feed rollers facilitate the delimbing of crooked tree stems. If necessary, the head can be slid past the crooks with the front knives open without losing grip of the trunk or delimbing efficiency.