Rules and specifications for dimension and woodwork.
The rules in this section apply to hardwood and softwood dimension components cut from kiln-dried rough lumber, bolts, cants or logs. They cover flat stock; solid, edge glued and squares; and solid and laminated for furniture, cabinet and specialty manufacturers.
These rules provide specifications for dimension components for domestic and export trade. They cover definition of product, general requirements, grades, scale, count, order method and tolerance of rough, semi-machined, and fully-machined parts. They also cover packaging, shipping, receiving, inspection and storage.
Definition of product
Dimension components as covered by these rules are defined as hardwoods and softwoods, normally kiln-dried, which have been processed to a point where the maximum waste is left at the dimension mill, and the maximum utility is delivered to the user. They are manufactured from rough boards, bolts, cants or logs of varying thicknesses to the specific requirements of a particular plant or industry. Components are in specified thicknesses, widths, and lengths, or multiples thereof. They may be solid or glued up as specified. They are classified as rough dimension, semi-machined dimension or fully-machined dimension.
Rough dimension consists of blanks cut and ripped to specific sizes, normally rough surfaced two sides or more to a nominal size.
Semi-machined dimension is rough dimension parts carried one or more steps further in manufacturing processes. It may include one or more of several operations such as finish surfacing, moulding, turning, tenoning, flat-sanding, equalizing, trimming, mitering, etc., but which will not make the product a completely machined part ready for assembly.
Fully machined dimension consists of parts that are completely machined with no additional work necessary prior to assembly. A final polish sanding operation may be required prior to finishing or painting.
All dimension parts sold as conforming to these rules shall meet the following general requirements.
Seasoning - Material shall be properly kiln dried according to accepted methods for the species and thickness to within a range of 5-9%. Uniformity of moisture content within a 3% variance (i.e., 6-8%) is most desirable, especially in the manufacture of glued parts. A low moisture content (5-7%) is desirable for parts manufactured and shipped during the winter season when plants are operating their heating systems and the relative humidity is lower. The same is true for parts being shipped to dry climates. Due to the tendency of wood to change in moisture content because of changes in atmospheric conditions, no specific moisture content can be guaranteed when dimension parts reach their final destination. Dimension manufacturers shall exercise all possible care in the seasoning, drying, handling and shipping of their products to assure delivery in a suitable condition.
Gluing - Dimension parts glued for width, length and/or thickness shall be bonded with high-grade glue and in such a manner as to provide strong joints. The type of glue and joint used shall be a matter of contract between buyer and seller.
Tempering - Glued stock will be tempered for the proper time required before surfacing and machining. This is to prevent sunken glue joints and stabilize the size prior to machining.
Workmanship - All dimension parts shall be well manufactured and shall conform to the various grades as hereinafter defined.
Thickness - The maximum finished thickness obtainable is dependent on the width of the piece. Table 1 indicates thicknesses which can be obtained from various thicknesses of rough lumber as related to width of stock.
Rough Rough Surf'd. Finish Surfaced 2 Sides
Less than 6 in. and 6 in. Wide Wider
Inches Inches Inches Inches
4/4 15/16 25/32 3/4 5/4 1 3/16 1 1/32 1 6/4 1 7/16 1 1/4 1 3/16 8/4 1 7/8 1 1/16 1 5/8 10/4 2 3/8 2 13/16 2 1/8 12/4 2 3/4 2 11/16 2 5/8
Rough - (RO) is sawmill cut.
Rough surfaced - (RS) is hit or miss planed or 20/36 grit abrasive that will clean up in subsequent finishing.
Finish surfaced - (FS) is a smooth uniform knife finish or 60 grit sander finish that will clean up with a .015 in.-flat sander cut. Finish surfaced can be surfaced two sides or surfaced four sides (S2S or S4S).
Moulded to pattern - (PAT) is moulded in the lineal direction to the customer's specification or drawing, inside of the line to govern.
End Work - Machined to customer specifications.
Shaping, Routing, Boring, Turning, etc. - are done per customer specifications.
In rough or semi-machined dimension parts of any grade, those blemishes that will be removed in planing or machining to finished sizes will be permitted. Flat stock dimension parts may be solid or edge glued, rough, rough surfaced or finish surfaced. Solid squares cut directly from bolts, cants or logs will be kiln dried after cutting. Laminated squares are cut from kiln dried lumber. Solid or laminated squares may be sold rough, rough surfaced or finish surfaced. In glued dimension parts, matching for direction of grain, figure and color, if required, shall be matter of agreement between manufacturer and user. Normally, staves with similar grain and color are together.
Face Grade - Hardwood
"A" Face - Material which is acceptable for prominent surfaces such as tops, doors and drawer fronts. This grade will permit small sound knot specks, small dark mineral streaks or pitch pockets up to 1/16 in. X 1 in., light discoloration, and strips from 1 in. min. to 5 in. max. in size, with narrow strips to be well scattered.
This grade will not permit birdseye, any knots other than small specks; splits checks or shake; holes, gouges or other open areas deeper than 1/32 in.; bark or wane; mineral streaks larger than 1/16 in. X 1 in.; large dark discolored areas; and punky or unsound wood.
"B" Face - Material which is acceptable for surfaces of intermediate visibility such as the exterior of most end panels, the interior of end panels on an open case, shelves and the inside of drawer fronts.
This grade will permit occasional pin knots and small sound knots not over 1/8 in.; occasional mineral streaks not over 1/4 in. X 2 1/2 in.; moderate discoloration; occasional birdseye; and strips from 1/2 in. min. to 5 in. max. in size - narrow strips to be well scattered.
This grade will not permit any knots over 1/8 in.; splits, checks or shake; holes, gouges or other open areas deeper than 1/32 in.; bark or wane; punky or unsound wood; mineral streaks over 1/8 in, X 1 1/2 in. and large dark discolored areas.
"C" Face - Material which is acceptable for low visibility parts where strength and smoothness is the deciding factor - such as back edges of rails, underside portion of any table that is susceptible to touch or feel.
This grade will permit unlimited discoloration or mineral streaks; solid knots up to 1/2 in. diameter; surface checks; open defects up to 1/8 in. X 1 in. or 1/4 in. diameter; unlimited birdseye; small areas of punky or unsound wood; and boards of any width up to 5 in.
This grade will not permit large open knots; wane; and large areas of punky or unsound wood.
Face Grade - Pine
"A" Face - Material which is acceptable for prominent surfaces such as tops, doors, and drawer fronts.
This grade will permit any number of round red knots up to 3 in. diameter (this type of knot is desirable and as many as possible should be included on the good side); splits within the knots are acceptable unless they seriously weaken the part and cannot be filled; occasional small black knots if they are tight and not over 1/4 in. in diameter-clusters of black knots are not acceptable; pitch or pitch pockets up to 1/8 in. wide by 1 in. long; and strips 1 in. min. to 6 in. max. in size - narrow strips to be well scattered.
This grade will not permit black knots larger than 1/4 in.; open or missing knots; splits, checks or shake; wane, bark or pitch; stain or discoloration; pitch pockets over 1/8 in. wide by 1 in. long; thin stock; and holes, gouges or other open areas deeper than 1/32 in.
"B" Face - Material which is acceptable for surfaces of intermediate visibility such as the exterior of most end panels, interior of end panels on open cases, shelves and center panels.
This grade will permit any size or number of round red knots (splits within the knot are acceptable and splits around the knot are acceptable up to two-thirds of the circumference of the knot); small black knots which are tight and not over 1/32 in. in diameter or larger knots which are only partially black; clusters of four or more black knots should be excluded; moderate discoloration; pitch or pitch pockets 1/8 in. wide by 1 in. long; strips 1/4 in. min. to 6 in. max. in size - narrow strips to be well scattered.
This grade will not permit splits, checks or shake; open or missing knots; wane or bark; and thin stock.
"C" Face - Material which is acceptable for low visibility parts when strength and smoothness is the deciding factor such as back edges of rails, underside portion of any table that is susceptible to touch and feel.
This grade will permit unlimited number and size of black knots; unlimited discoloration; pitch pockets; small surface checks; and boards of any width up to 7 in.
This grade will not permit large open knots or holes; and large areas of punky or unsound wood.
Paint (PNT) - This grade will permit, on the best face, defects such as burls and tight knots which, when properly filled, will be concealed when finished with non-transparent material. The reverse face or back may contain defects of a sound grade, patches, and slight imperfections in surfacing.
Sound (SND) - This grade is a utility grade that may contain any defects that will not materially impair the strength of the individual piece for the use intended. Slight skips in dressing on either face will be permitted.
A key purpose of these standards is to provide a system where the buyer can choose only those grades that meet his needs and not overspecify which adds unnecessarily to the product cost. Considering the natural characteristics of wood, it is the dimension manufacturer's objective to always maximize his utilization thus reducing the material cost to the customer. The following codes are used to simplify specifying: AF = All Faces, FE = 1 Face and 4 Edges, 1F = 1 Face, 1E = 1 Edge, 1F1E = 1 Face and 1 Edge, PNT = Paint Grade, SND = Sound Grade.
List of Grades
AAF = "A" All Faces BAF = "B" All Faces CAF = "C" All Faces AFE = "A" 1 Face 4 Edges, "B" Back BFE = "B" 1 Face 4 Edges, "C" Back CFE = "C" 1 Face 4 Edges, Sound Back A1F = Remainder Sound B1F = Remainder Sound C1F = Remainder Sound A1E = Remainder Sound B1E = Remainder Sound C1E = Remainder Sound A1F1E = Remainder Sound B1F1E = Remainder Sound C1F1E= Remainder Sound
As referred to in this section the word SCALE shall mean the footage content that the customer is charged for in each piece of dimension.
Flat Stock Solid and Edge Glued
Thickness - In computing the footage of dimension components, the rough nominal thickness required for its manufacture is used. Surface measurement is to apply on rough 1-in. and thinner lumber, and board foot measurement is to apply on lumber over 1-in. rough thickness.
Width - In computing footage when edges are surfaced, molded, or sawed to net width(*), 1/4 in. shall be added to the net finished width if under 6 in. wide and under 50 in. long. If 6 in. or wider, all lengths, and 50 in. or longer, all widths, 1/2 in. shall be added to the net finished width. If widths are in fractions of less than eighths of an inch, assume the next higher 1/8 in. All pieces having a net width of 3/4 in. or under shall be counted as 1 in. wide.
Length - For dimension parts supplied in rough lengths, 1 in. shall be added to net finished length. If lengths are in fractions, the measurement shall be to the nearest 1/4 in. with 1 in. to be added for equalizing. For those measurements falling exactly at midpoint between quarters of an inch, the lower quarter shall be used.
Example of Scale, Flat Stock
Required Sizes Measured As
3/4 X 1 1/2 X 22 1 X 1 3/4 X 23 3/4 X 1 1/2 X 51 1 X 2 X 52 3/4 X 1 5/16 X 23 1/8 1 X 1 5/8 X 24 7/16 X 4 5/8 X 30 1 X 4 7/8 X 31 7/16 X 7 1/4 X 25 1/8 1 X 7 3/4 X 26 5/16 X 6 3/16 X 18 9/16 1 X 6 3/4 X 19 1/2 5/16 X 8 9/16 X 21 11/16 1 X 9 1/8 x 22 3/4 1 X 2 1/4 X 36 1 1/4 X 2 1/2 X 37
In laminated stock, exact specifications as to number of plies shall be determined between the producer and customer. In the absence of this specification, the number of plies used shall be based upon the most economical manner to produce required thickness.
Thickness - When stock is laminated, each ply is to be figured from the rough thickness necessary to produce the dressed piece as set forth in Section 3.6.
Width - In laminated stock, the width shall be figured 1/4 in. over the net width in two-ply stock, and 1/2 in. over in three-ply stock or more.
Length - When laminated stock is equalized, 1 in. shall be added to the net length.
Example of Scale - Squares, Laminated
Required Sizes (Count As) Made From:
1 5/8 X 1 5/8 X 29 2 X 1 7/8 X 30 2 Pcs. 4/4[inches] 2 1/16 X 3 1/8 X 29 2 1/2 X 3 3/8 X 30 2 Pcs. 5/4[inches]
2 3/8 X 2 3/8 X 29 3 X 2 7/8 X 30 3 Pcs. 4/4[inches] 3 X 3 X 29 3 3/4 X 3 1/2 X 30 3 Pcs. 5/4[inches] 3 3/16 X 6 X 45 3 3/4 X 6 1/2 X 46 3 Pcs. 5/4[inches] Examples of Scale - Squares, Solid
Required Sizes Sizes of Rough Blank S4S Equalized: to produce
3/4 X 3/4 X 15 4/4 X 1 X 16 1 3/8 X 1 3/8 X 20 8/4 X 1 5/8 X 21 2 X 2 X 30 10/4 X 2 1/4 X 31
Rough - Squares shall be of sufficient size after kiln drying to surface four sides to the following thicknesses: 4/4 S4S 25/32 in., 5/4 S4S 1 1/32 in., 6/4 S4S 1 1/32 in., 8/4 S4S 1 11/16 in. These squares shall be measured on the basis of the rough lumber required to produce them.
Dimensions parts shall be ordered in specific quantities in terms of number of pieces, sets of pieces, lineal feet of random length or number of feet. The manufacturer will ship the order complete, with no back orders, unless previously agreed to by the buyer. The buyer shall accept up to 5% overrun in pieces, feet or sets of pieces if ordered in sets, in any or all items ordered.
In the absence of other requirements by the customer, the following steps for writing orders shall be followed: Quantity, the thickness, width, length, grade, machining and any other specifications required by the customer. Sizes shall be in ascending order with similar thicknesses grouped thinnest first, then all parts of the same width, and lengths from shortest to longest.
Qty Th Width Length Machining Grade
100 25/32 X 2 X 14 FS S4S AFE 150 25/32 X 2 X 19 FS S4S AFE 500 25/32 X 2 X 20 1/4 FS S4S AFE 300 25/32 X 2 1/4 X 16 FS S4S AFE 350 1 1/32 X 2 1/2 X 18 1/2 FS S2S B1F
Tolerances for rough hardwood dimension parts shall be agreed upon by customer and seller.
Rough Surfaced Dimension
Unless otherwise agreed upon by customer and seller, sizes which will be changed in the process of further fabrication by the customer shall be subject to the following tolerances:
Thickness Plus 1/16 inch Minus 1/16 inch Width Plus 1/16 inch Minus 1/16 inch Length Plus 1/8 inch Minus 1/8 inch
Semi Machined and Fully Machined Dimension
In machine dimension a normal tolerance of plus or minus 1/32 in. will be allowed in all machining operations at time of working unless otherwise specified. Mating parts shall meet requirements agreed to by the buyer and seller. It should be recognized that atmospheric conditions may cause a later change in dimensions over which manufacturers have no control.
Packaging and Shipping
Packing and shipping shall be in accordance with methods accepted in the trade to ensure proper protection of the product in transit. Any variations and special requirements shall be a matter of agreement between the buyer and seller.
Receiving and Inspection
No complaint shall be justified unless the number of dimension parts not meeting specification exceeds 2%. No claim shall be honored on material that has been machined by the customer.
Purchasers of dimension parts, upon receipt of shipments and prior to further machining and processing, shall handle and store the stock in a manner customarily accepted in the trade in order to prevent the occurrence of degrade. This shall include protection against moisture and temperature changes as well as physical damage.
In case of complaint, the purchaser shall notify the seller within 5 days after receipt of shipment. Any rejected material shall be held intact, properly protected, in its original form for a period up to 3 weeks after notice of rejection, and pending adjustment.
In case of complaint, the purchaser shall notify the seller, by cable, within 2 days after receipt of shipment, and shall make a supporting detailed written report within 5 days after such goods have been received by the purchaser. Any rejected material shall be held intact, properly protected, in its original form for a period up to 5 weeks after notice of rejection, and pending adjustment. Any inspection shall be made by a party agreed upon by the purchaser and seller with complete reports being given to both.
Hardwood Interior Trim and Molding
All hardwood interior trim and molding sold as conforming to this standard shall be clear-face trim, except where characteristics of the wood and seasoning defects, as hereinafter specified, may be present in not to exceed 10 percent of any shipment. It shall be well manufactured in accordance with the following requirements.
Seasoning - Material shall be kiln-dried according to accepted methods for the species in question to a moisture content which shall be 5 to 9% when shipped from the mill.
Workmanship - All woodwork shall be well manufactured and shall conform to the various grades hereinafter defined.
Grading - All hardwood interior trim and molding shall be graded from the face side.
Allowable Characteristics - Those characteristics covered by member moldings, or covered when the stock is installed, and characteristics on the reverse side that do not impair its use shall be allowed.
Detail Requirement - Grade "A"
The characteristics and seasoning defects allowed in any one piece shall be only as covered by not more than any two of the following paragraphs.
Sapwood - Sapwood shall be allowed in all items of hardwood interior trim and molding, except when made from cherry, selected red birch, red gum, or unsteamed walnut. In these woods the sapwood shall not exceed 25% (surface measure) in the aggregate in any one piece and not more than 5% of the quantity of any one item (pattern, style, or total of same kind of units). This grade is suitable for natural and highest quality paint finishes.
Stain - Stain covering not more than 25% in any one piece (surface measure), and not more than 5% of the quantity of any one item, shall be allowed.
Streaks - Slight streaks shall be permitted in not more than 10% of the quantity of any one item.
Worm holes - Worm holes not larger than 1/16 in. in diameter, and not more than true to each 3 linear feet, shall be allowed. Maximum quantity of material containing worm holes shall not exceed 5% of the quantity of any one item.
Knots - One knot, tight, sound and smoothly dressed, not to exceed 1/2 in. greatest diameter, in stock 6 ft. long or less, and not more than two in stock over 6 ft. long shall be allowed. Maximum quantity of material containing knots shall not exceed 5% of the quantity of any one item. Burls that do not contain knots over 1/8 in. in diameter or unsound centers shall not be considered a defect.
Machine imperfections - Slight machine imperfections which can be eliminated by hand-sanding shall be allowed.
Torn grain - A maximum depth of 1/32 in. will be permitted on machine-run stock in not over 10% of the length in any one piece and not more than 5% of the quantity of any one item.
End splits - End splits 1/4 in. in length for each linear foot, or its equivalent, per piece will be allowed, except that where exact lengths are specified, stock shall be usable for the purpose intended, without waste.
Surface checks - Surface checks not to exceed 1/32 in. wide, 1 in. long, and one check to each foot (surface measure), or its equivalent, per piece, shall be allowed. Maximum quantity of material containing surface checks shall not exceed 5 percent of the quantity of any one item.
Warp - Warped stock that will lie flat or straight with ordinary nailing shall be allowed.
Detail Requirement - Grade "B"
This grade shall be the same as grade "A" except that when sold and marked "grade B," there shall be no restriction as to sapwood and stain in any of the species, as this grade is normally confined to a paint finish.
Designs and Sizes
Standard design and sizes shall conform to Industry Standard Wood Moulding Patterns, latest edition, as published by the Wood Moulding and Millwork Producers, P.O. Box 25278, Portland, Oregon 97225, (503) 292-9288.
Special design - Shall be: As per full size detail drawing (inside of line of govern); as per template (stock must fit flush, not tight at time of machining); or as per sample.
Special sizes - Shall be as specified.
Random lengths - Length 4 to 16 ft. shall be counted on 6-in. breaks. Each shipment may contain not more than 20% of lengths under 8 ft. 5% may consist of lengths under 6 ft. A variation of 5% over or under the quantity ordered, in linear feet on random-length orders will be allowed.
Specified lengths - When specified lengths are ordered, all lengths up to and including 4 ft. 6 in. shall be counted on 6-in. breaks. Example: Stock 3 ft. 2 in. long will be counted as 3 ft. 6 in.; 4 ft. 6 in. long will be counted as 4 ft. 6 in. Lengths over 4 ft. 6 in. shall be counted on 6-in. breaks, to which an additional 6 in. shall be allowed for cutting. Example: Stock 4 ft. 7 in. long will be counted as 5 ft. 6 in.; 7 ft. long will be counted as 7 ft. 6 in.
Tolerance - A variation in size of 1/32 in. plus or minus will be allowed for all unsanded hardwood interior trim and molding, with an additional allowance of 1/32 in. scant for machine sanding.
Bundling - Molding shall be bundled and measured by averaging the lengths, which may vary 6 in. over or under the nominal length.
Hardwood interior trim and molding shall be sold on a linear foot basis.
All hardwood interior trim and molding sold as conforming to this commercial standard is subject to inspection in the condition as received, and complaints regarding any shipment shall be made within five days after receipt thereof. Any rejected material shall be held intact in its original form, properly protected, for a period up to three weeks after notice of rejection and pending adjustments.
Hardwood Stair Treads and Risers
All hardwood stair treads and risers sold as conforming to this standard shall be well manufactured in accordance with the following requirements:
Seasoning - Material shall be kiln-dried according to accepted methods for the species in question to a moisture content not to exceed 7% when shipped from the mill.
Workmanship - All woodwork shall be well manufactured and shall conform to the various grades hereinafter defined.
DETAIL REQUIREMENT - STANDARD GRADES
Hardwood stair treads and risers shall be graded according to the face, side and nosing. The reverse side of all grades may contain imperfections and characteristics which do not materially impair the strength. The standard grades for hardwood stair treads and risers, which may be glued-up for width or one piece, shall be as follows:
Clear grade - The tread nosing and the face of treads and risers shall be clear and free of sapwood. In glued-up stock, the pieces shall be well-matched for color and grain. Streaks may be admitted, but not more than two in any one tread or riser and not over 6 in. long in the aggregate.
Select grade - The tread nosing and the face of treads and risers may contain slightly chipped grain; streaks; bright sapwood; sound tight knots not over 1/4 in. in diameter and not more than two in each piece, spot-worm holes 1/16 in. in diameter or less, to the extent of one per linear foot.
Character - marked grade - The tread nosing and the face of treads and risers shall display various character markings inherent. The character markings may include tight knots, worm holes, bird pecks, swirls, burls and other grain irregularities, stain, streaks and other color variations occurring in the growth of the wood. It shall be free from rot, decay, and heart center.
Paint grade - This grade covers risers only which are intended for a paint finish. The face may contain tight knots, stain, or other sound imperfections which do not materially impair the strength or which would prevent a smooth paint finish. Open defects when properly filled and sanded shall be permitted.
Stair treads are available in Clear Grade, Select Grade, and Character-marked Grade.
Thickness - The standard thickness for treads shall be 1 in. after molding, less customary allowance for sanding. Special thicknesses of 25/32 in. and 1 5/16 in. may also be graded according to this standard.
Width - The standard widths for treads shall be 9 1/2 in., 10 1/2 in., and 11 1/2 in. The width shall be measured from the extreme point of the nosing to the back edge.
Length - The standard length for treads shall be 3 ft., 3 ft. 6 in. 4 ft., 4 ft., 6 in. and 5 ft.
Stair risers are available in Clear Grade, Select Grade, Character-Marked Grade, and Paint Grade.
Thickness - The standard thickness of risers shall be 3/4 in. after molding, less customary allowance for sanding.
Width - The standard widths of risers shall be 6 1/2 in., 7 in., 7 1/2 in., and 8 in.
Length - The standard lengths of risers shall be 3 ft., 3 ft. 6 in., 4 ft., 4 ft. 6 in., and 5 ft.
A manufacturing tolerance of plus or minus 1/32 in. in the thickness, width, and length shall be allowed. All treads and risers shall be furnished with square ends and with side edges parallel.
All hardwood stair treads and risers sold as conforming to the commercial standard are subject to inspection in the condition as received, and complaints regarding any shipment shall be made within five days after receipt thereof. Any rejected material shall be held intact in its original form, properly protected, for a period up to three weeks after notice of rejection and pending adjustments.
* "Sawed to net width" refers to stock sawed on a straight line ripsaw or double-end tenoner, producing a piece of stock in which the edge is satisfactory for its ultimate use.
RELATED ARTICLE: PUT THE RULES IN YOUR POCKET
The Wood Component Manufacturers Association offers a handy pocket-size version of the "Rules nd Specifications for Dimension and Woodwork" for $5 a copy. The pamphlet includes a guide to industry standard abbreviations and glossary of terms. For ordering information, contact:
WCMA 1000 Johnson Ferry Road Suite A-130 Marietta, GA 30069 Phone: (770) 565-6660 Fax: (770) 565-6663
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|Publication:||Wood & Wood Products|
|Date:||Jul 1, 1996|
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