AN SI A135.4-2004 Approved March 11 , 2004



# Basi HardboardANSI A135.4-2004, Basic Hardboard



### American National Standard

Published by Approval of an American Standard requires verification by the American National Standards Institute (ANSI) that the requirements for due process, consensus, and other criteria for approval have been met by the standard's developer. Consensus is established when, in the judgement of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution.
The use of American National Standards is completely voluntary; their existence does not in any respect preclude anyone, whether they have approved the standards or not, from manufacturing, marketing, purchasing, or us ing products, processes, or procedures not conforming to the standards. ANSI does not develop standards and will in no circumstance give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations should be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this standard. Purchasers of American National Standards may rece ive current information on all standards by calling or writing the American National Standards Institute.

Composite Panel Association 18922 Premiere Court, Gaithersburg, MD 20879-1574 Copyright© 2004 by Composite Panel Association All rig hts reserved.
No part of this publication may be reproduced i n any form, in an electronic retrieval system or otherwise , without prior permission of the Composite Panel Association. Printed i n the Un ited States of AmericaANSI A135.4-2004 Basic Hardboard



### Abstract This Standard defines hardboard, covers requirements and test methods for water absorption, thickness swelling, modulus of rupture, tensi le strength, surface finish, dimensions, squareness, edge straightness, and moisture content of five classes of bas ic hardboard. Where appropriate, test methods in ASTM D 1037 are required. Methods of identifying hardboard that conforms to this Standard are provided. (This Foreword is not a part of American National Standard 

### Foreword for Basic Hardboard.) Basic hardboard has numerous uses, from wall paneling to furniture components, to a variety of utility boards for home and industry. This Standard was originally promulgated under the procedures of the U .S. Department of Commerce National Bureau of Standards and designated as Voluntary Product Standard PS 58-73. The 1982 revision was published with adjustments to physical properties listed in Table I which reflected the state of the art. In 1988 the Standard was reaffirmed without change

. The 1995 revision made editorial corrections and added metric equivalents. This 2004 revision makes only editorial changes. The development of this American l\Jational Standard for Basic Hardboard offers manufacturers, consumers, and the general public concerned with the product an effective quid e developed under the consensus procedures of the American National Standards Institute.
Consensus for this standard was achieved by use of a canvass body and ANSI's Essential Requirernents for due process
. The following organizations, recognized as having an interest in hardboard standards, were contacted prior to the approval of this standard. Inclusion i n this list does not necessarily imply that the organization concurred with the subm ittal of the proposed standard to ANSI. AFCO Industries Inc. Mason ite International Corporation AKZO Nobel Coatings, Inc. Institute for Building Technology and CraftMaster Manufacturing, Inc. Safety Georgia-Pacific Corporation Stimson Lumber ICC Evaluation Services, Inc. Stork

- Twin City Testing Corp. Jeld-Wen R&D Temple-Inland Kitchen CabinetManufacturers Assn. USDA Forest Products Laboratory Louisiana-Pacific Corporation Un iversity of Illinois Manufactured Housing Institute

2ANSI A135.4-2004 Basic Hardboard

1. SCOPE This Standard covers requirements and methods of testing for the water resistance, modulus of rupture, tensile strength, surface finish, dimensions, squareness, edge straightness, and moisture content of five classes of basic hardboard

. Hardboard siding and prefinished hardboard paneling are covered by separate American National Standards. Methods of identifying hardboard that conforms to this Standard are provided.

2. DEFINITION 2.1. Basic Hardboard. Hardboard is a panel manufactured primarily from i nt e r - f e lt ed lignocellulosic fibers which are consolidated under heat and pressure in a hot-press to a density of 500 kg/m 3 (31 

### lbs/ft' ) or greater. Other materials may be added to improve certain properties, such as stiffness, hardness, finishing properties, resistance to abrasion and moisture, as well as to increase strength, durability, and utility. 2.2. Surface. Hardboard panels are available with either one (SlS) or two (S2S) smooth sides.

3. REQUIREMENTS 3.1. General. All hardboard represented as complying with this Standard shall meet all of the requirements specified herein. The inspection and test procedures contained i n this section are to be used to determine the conformance of products to the requirements of this Standard. 3.2. Classes. The hardboard shall be classified based on the physical properties shown i n Table 1. The properties shall be determined in accordance with the applicable test methods in Part B of the American Society for Testing and Materials (ASTM) D 1037-99 Test Methods for Evaluating the Properties 

### of Wood- Base Fiber and Particle Panel Materials, except that, when testing modulus of rupture, specimens greater than 9.5 mm (3/8 inch) thick shall be tested according to Part A, Section 14 of this reference. 3.3. Surface Finish. The smooth surfaces shall be as free from visible variations in the surface plane as commercially practicable when visually inspected by an individual competent in the field 3.4. Dimensions and Tolerances. The hardboard panels shall have a nominal width of 1220 mm or 1524 mm (4 feet or 5 feet). The nominal length of the panels shall be as agreed upon by the purchaser and the seller. The tolerance on the nominal width and length shall be plus or minus 1.6 

### mrn/rn (1/64 inch/linear foot). The nom inal thicknesses shall be as designated in Table 2. Thickness ranges shall be as specified in Table 2 when measured in accordance with the appl icable test method in Part B of ASTM 

### D 1037­ 99.

3ANSI A135.4-2004 Basic Hardboard

3.5. Squareness. The length of the diagonals of the hardboard panels shall not vary by more than 1.6 rnrn/rn (1/64 inch/foot) of length of the panels. Opposite sides of the panels shall not vary in length more than 3.2 mm (1/8 inch). 3.6. Edge Straightness. The edges of the hardboard panels shall be straight within 1.6 

### rnrn/rn (1/64 inch/foot) of length or width. Edge straightness shall be determined by stretching a string or w i re from one corner and measuring the widest distance between the string or wire and the panel edge being tested. 3.7. Moisture Content. The moisture content of the hardboard shall be not less than 2 percent nor more than 9 percent and, within anyone shipment, shall not vary by more than 3 percent age points as measured by the moisture content of the modulus of rupture specimens. Moisture content shall be determined in accordance with the applicable test method in Part B of ASTM D 1037-99. Since hardboard is a wood-base material, its moisture content will vary with environmental humidity cond itions. When the humidity conditions in the area of intended use are a critical factor, the purchaser should specify a moistu re content ra nge more restrictive tha n 2 to 9 per cent so that fluctuation in the moisture content of the panel will be kept to a m inimum. 3.8. Marking and Identification. All basic hardboard which is represented as conforming to this Standard shall be identified by either of the following methods when requested by the purchaser: (a) Each board shall be marked with a colored vertical stripe or stripes which indicates the class of the board. The marking for the different classes shall be as follows:

Number and Class color of stripes Tempered 1 Red Service Tempered 2 Red Standard 1 Green Se rv ice 2 Green Industrialite 1 Blu e
The stripe or stripes shall be applied to the four edges of a board as follows: On the short sides of the board, the stripe should be appl ied 75 mm (3 inches) from the left hand corner (as determined when the marker faces the side being marked); on the long sides of the board , the stripe should be applied 75 mm (3 inches) from the right hand corner as determined when the marker faces the side being marked. See Figure 1 for an example of the placement of the markings. Stripes shall be 13 mm (1/2 inch) in width. When two stri pes are used they sha II be 25mm (1 inch) apart

.

4ANSI A135.4-2004 Basic Hardboard

Figure 

### 1. A stack of hardboard showing placement ofmarkings.
(b) The shipment or order shall be accompanied by a written certification stating the class of the hardboard and that the hardboard conforms to the requirements of this Standard

.

5ANSI A135.4-2004 Basic Hardboard

Table 1 Classification of Hardboard by Thickness and Physical Properties

Class

1 Tempered

2 Standard

3 Service

-Tempe red

4 Service

5 Industrial ite Nom inal thickness

mm inch 2.1 1/12 2.5 1/ 10 3. 2 1/ 8 4.8 3/1 6 6.4 1/4 7.9 5/ 16 9

.5 3/8 2. 1 1/12 2

.5 1/10 3. 2 1/ 8 4.8 3/16 6.4 1/4 7.9 5/16 9

.5 3/ 8 3 .2 1/ 8 4.8 3/ 16 6.4 1/4 9 .5 3/8 3.2 1/8 4.8 3/16 6.4 1/4 9 .5 3/8 11.1 7/ 16 12.7 1/2 15.9 5/8 6.4 1/4 9 .5 3/8 11.1 7/ 16 12.7 1/2 15.9 5/ 8 Wat er res istan ce Tensile st rength ( max . ave rage per pane l) Modulus of (m in

. aver age per panel) Water absorption based on

wei ght Th ickness Swelling rupture (min

. average per pan el) Parallel to sur face Perpend icul ar to su rfa ce percent percent MPa psi MPa psi MPa psi

30 25 25 20 25 20 25 20 41.4 6000 20 .7 3000 0

.90 13 0 20 15 15 10 10 9 40 30 35 25 35 25 35 25 31.0 4500 15.2 2200 0.62 90 25 20 20 15 15 10 35 30 30 30 30 25 3 1.0 4500 13.8 2000 0

.52 75 20 15 45 35 40 35 40 30 35 25 20. 7 3000 10.3 1500 0

.34 50 35 25 30 20 25 20 50 30 40 25 40 25 13 .8 2000 6.9 100 0 0.17 25 35 25 30 20

6ANSI A135.4-2004 Basic Hardboard
Table 2 Thickness Ranges for hardboard Panels

Nominal Thickne ss

mm i nch
2

. 1 1/12 (0.083) 2.5 1/10 (0 .100) 3.2 1/8 (0 .125)
4 .8 3/16 (0 .188)
6 .4 1/ 4 (0 .250)
7 .9 5/16 (0.312) 9.5 3/8 (0 .375) 11.1 7/16 (0.438) 12

.7 1/2 (0.500) 15 .9 5/8 (0 .625) Th ickness Range (min. -max .)

mm i nch 1. 8 - 2. 3 0 .070

- 0.090 2.3 - 2 .8 0.09 1 - 0.110 2.9

- 3.9 0

. 11 5

- 0 .155
4 .2 - 5 .2 0.1 65 - 0.205 5.3

- 6.7 0 .210

- 0.265 7.4

- 8.5 0.290

- 0.335 8.9

- 10 .2 0.350 - 0 .400 10.4

- 11.7 0.410 - 0 .460 12.1

- 13.3 0 .475

- 0.525
15.2

- 16.5 0.600

- 0.650

7

# COM POSITE PANEL A SSOCIATION

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he Composite Panel Association (CPA) was founded in 1960, and represents the North American industry on technical, regulatory, quality assurance and product acceptance issues

. Membership currently includes 37 of the leading producers of industry products. Together they represent 92% of the total manufacturing capacity of North American particleboard (PB) , medium density fiberboard (MDF), hardboard (HB) and other compatible products.

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