| Product |
Grade |
Grade Characteristics and
Typical Uses |
* Mechanically Graded Lumber - Machine Street Rated (MSR) Lumber: 2"
and less in thickness, 2" and wider
See table 3 for design values |
|
1650f - 1.5E |
Machine Stress Rated
(MSR) lumber is lumber that has been evaluated by mechanical stress rating equipment. MSR
lumber is distinguished from visually stress graded lumber in that each piece is
non-destructively tested. MSR lumber is also required to meet certain visual grading
requirements. |
| thru |
| 3000f - 2.4E |
* Mechanically Graded Lumber - Machine Street Rated (MEL): 2" and
less in thickness, 2" and wider
See SPIB Grading Rules for design values |
|
M-5 thru M-28 |
Well-manufactured material
evaluated by calibrated mechanical grading equipment which measures certain properties and
sorts the lumber into various strength classifications. Machine Evaluated Lumber is also
required to meet certain visual requirements. |
*Scaffold Plank: 2" and 3" thick, 8" and wider
See table 4 for design values |
|
Dense Industrial 72 |
All Scaffold Plank
design values are calculated using ASTM Standards D245 and D2555. These values are
modified using procedures shown in "Calculating Apparent Reliability of Wood Scaffold
Planks," as published by the Journal on Structural Safety, 2 (1984) 47-57. |
| Dense Industrial 65 |
|
MSR: 2400f-2.0E |
Dressed to standard
dry size prior to machine stress rating, and visually graded to assure that
characteristics affecting strength are no more serious than the limiting characteristics
for each grade. MSR Scaffold Plank is available 2" thick only. |
| MSR: 2200f-1.8E |
*Stadium Grade: 2" thick, 4" to 12" wide
See table 1 for design values |
|
No. 1 Dense |
For outdoor seating,
Free of pitch pockets, pitch streaks and medium pitch on one wide face, but otherwise
conforms to No. 1 Dense or No. 1 Dimension Lumber. |
| No. 1 |
*Prime Dimension: 2" to 4" thick, 2" to 12" wide
See table 1 for design values |
|
No. 1 Prime |
Grade based on No. 1 Dimension
Lumber characteristics except that holes, skip and wane are closely limited to provide a
high-quality product. |
|
No. 2 Prime |
Grade based on No. 2 Dimension
Lumber characteristics except that holes, skip and wane are closely limited to provide a
high-quality product. |
| *Most mills do not
manufacture all products and make all grade separations. Those products and grades not
manufactured by most mills are noted with an asterisk. |
