Low-friction harvester heads spanning thinning through to heavy processing. SP publishes highest-productivity DBH ranges alongside maximum cutting capacity, which makes its specification sheets unusually useful for commercial comparison.
SP Maskiner builds low-friction harvester heads spanning thinning through to heavy processing, and its specification practice is unusually valuable to commercial buyers: it publishes highest-productivity DBH ranges alongside maximum cutting capacity.
That is rarer than it should be, and it makes honest comparison possible. The SP 661 LF cuts to 700 mm with an optional system to around 810 mm — but SP states its highest-productivity range as approximately 160-510 mm. The SP 761 LF cuts to 800 mm with a recommended optimum of roughly 250-500 mm depending on configuration.
For a buyer, those second numbers are the commercial specification. They describe where the head spends its working life rather than what it can occasionally do.
An equipment reference that only says where a brand fits is a brochure.
For commercial forestry the dealer is part of the equipment. Entries marked as confirmed were checked against the supplier's own published information.
Harvester head manufacturers publish three separate diameter figures, and conflating them is the most expensive specification error in Australian forestry.
The first is the optimum production range — the diameter band in which the manufacturer states the head is most productive. The second is the recommended maximum regular DBH, the largest stem the head should handle routinely. The third is the absolute maximum cutting capacity, which describes what it can occasionally sever.
Buyers routinely quote only the third, and it is the least useful of the three. A head with a 700 mm cutting capacity and a stated highest-productivity range of roughly 160-510 mm spends its entire working life in the second figure, not the first. Specifying against the maximum means paying for weight, carrier class and component cost that never converts into production.
Get all three in writing, then measure your own stand — average DBH, 90th-percentile DBH and maximum DBH — and match the optimum range to where the bulk of your volume actually sits. Manufacturers that publish optimum ranges are making honest comparison possible; use it.
Where another supplier would genuinely serve the same requirement better.
Published specifications, commercial fit and verification points for each.
Benchmark specifications, buying criteria and specification traps for each class.