5. One of the world's most versatile softwoods

A Technical and Comparative Study of Radiata Pine and North American Timbers

New Zealand's Radiata pine is one of the world's most versatile softwoods - an ideal material for a wide range of commercial applications. The timber's status as a good quality, multi-application resource has been endorsed by a recent comparative study with 13 North American timbers. All have similar characteristics and uses.

A comprehensive series of tests evaluated the timbers in terms of their machining and related mechanical properties. Radiata pine achieved first place with an overall score of 70% - against an average score of 60%.

Radiata pine was compared with 13 North American timbers sourced by the University of California, Berkeley, and widely used in the manufacturing and construction industries. The study was undertaken by the New Zealand Forest Research Institute in collaboration with the University of California, Berkeley.

An extensive series of tests formed the basis for the comparison. Using techniques of the American Society for Testing and Materials (ASTM), tests were designed to evaluate the timbers in terms of their machining and related mechanical properties.

The tests were specifically selected to assess the timbers' suitability for panelling, mouldings, joinery and furniture manufacture and included evaluations in planing, shaping, turning, sanding and gluing.

Each species was represented by a batch of 20 lengths of 19mm thick lumber conditioned to 8% equilibrium moisture content.

The Radiata pine was of average quality in terms of wood density and stand history. The trees were 33 years old at the time of felling and had been thinned three times in that period to maintain growth rates. They had also been pruned at three stages - a technique designed to promote the recovery of clear grades of lumber. This treatment is typical of most of Wenita's Radiata pine.

Each test was carried out on 20 samples per species. The mean results were graded from 5 to 1, with 5 being the highest score. To provide the timbers with an overall rating, each test was given a weighting of 1 or 2 according to the perceived importance of each characteristic being tested.

Table of Overall Results:

Plan-
ing		 Shap-
ing		 Turn-
ing		 Cross-
Cutt-
ing		 Bor-
ing		 Mort-
ising		 Sand
ing		 Finger-
Joint-
ing		 Glue-
ing		 Hard-
ness		 Nail-
with-
draw		 Nail-
Split-
ting		 Screw-
Split-
ting		 Stab-
ility
OA Rating %
weighting
2
2
2
1
1
1
2
1
2
1
1
1
1
2
-
Radiata Pine
8
10
6
4
3
4
8
4
8
3
2
2
4
4
70
Short Leaf Pine
2
8
6
4
3
5
8
4
6
3
2
2
4
2
59
Sugar Pine
6
8
4
4
3
3
8
5
6
2
1
4
5
8
67
Western White Pine
4
6
6
4
2
4
4
5
6
2
1
2
4
2
52
Ponderosa Pine
4
10
4
4
3
5
8
5
6
2
1
4
5
4
65
Red Pine
6
10
4
3
2
5
10
5
6
2
1
3
5
2
64
Eastern White Pine
6
10
6
3
3
4
6
5
6
2
1
3
5
2
62
Loblolly Pine
4
8
2
3
2
5
8
4
6
3
2
2
4
2
55
White Fir
2
6
2
4
2
2
8
5
6
2
2
2
4
4
51
Douglas Fir
4
10
2
5
2
5
8
5
6
2
2
2
5
6
64
Western Hemlock
2
6
2
4
2
4
8
4
6
2
2
2
4
4
52
Red Alder
8
10
4
2
3
5
4
4
8
3
2
2
5
2
62
Yellow Poplar
6
10
8
4
3
5
6
4
8
3
3
1
5
2
68
Eastern Cottonwood
2
4
4
2
3
5
2
4
6
2
2
3
5
2
46
Average:
60%

Source : NZ Forest Research Institute