WINDOW & DOOR MANUFACTURERS ASSOCIATON

WDMA T.M. 10-20082014(draft)

TEST METHOD

FOR DETERMINING THE SCREWHOLDING

CAPACITY OF WOOD DOORS

Published By

Window and Door Manufacturers Association

330 N. Wabash Avenue, Suite 2000, Chicago, IL 60611

2025 M Street NW, Suite 800, Washington, DC 20036® Copyright 20082014

Editorial edits September 2009

No part of this publication shall be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission of the publisher.

  1. SCOPE

This test method determines the ability of a wood door (vertical edge, horizontal edge and face) to resist the withdrawal of a screw perpendicular to the surface.

  1. APPLICABLE DOCUMENTS
  2. ASTM D1761-0612, Standard Test Methods for Mechanical Fasteners in Wood
  3. ANSI B18.6.4-1998(R2005), Thread Forming and Thread Cutting Tapping Screws and Metallic Drive Screws.
  4. SIGNIFICANCE AND USE

This test method will provide useful data for designers, specifiers, and manufacturers in making judgements on the ability of the door assembly to maintain serviceability under operating conditions.

  1. APPARATUS

Any testing machine (Instron or equivalent) capable of applying a load at a uniform rate motion at a rate of 0.10 inches [2.5mm] per minute. The equipment must be capable of recording the load required to withdraw the screw.The assembly shall be similar to Figure 2.

  1. TEST SPECIMEN
  2. A complete test series shall consist of ten (10) specimens, selected at random, representative of actual pre-fit door construction. Specimens are referenced in Figure 1 for Sections 5.2, 5.3 and 5.4,and shall not be beveled.
  3. Vertical Edge Samples:Cut no more than one (1) 3”[76 mm] specimen from each 30” [762 mm]of door hinge stile edge for each test series, and selected from random locations. No specimen shall include portions of end rails or optional blocking. The width (Dimension “A”) of the individual stile component shall be measured and recorded in the test results. The specimen shall be prepared for testing as follows:
  4. Cut and remove 0.134” ± 0.005”[3.4 mm ± 0.1 mm] for 1-3/4” [44.5 mm] pre-fit doors or 0.105” ± 0.005” [2.7 mm ± 0.1 mm] for 1-3/8” [34.9 mm] pre-fit doors, from the exterior surface of the vertical edge to simulate the removal of material in preparing for the hinge leaf.
  5. Where remaining stile or stile/core material is greater than 1”, cut and remove enough material from the interior surface to yield a specimen width of 1" (Dimension “A”).Where stile edgeis less than 1”, no additional trimming is required.
  6. The screws shall be appropriate for the size of the test specimen in accordance with the following:

Specimen ThicknessScrew Size

1-3/8” [34.9 mm] #10 Type AB (Section 2.2)

1-3/4” [44.5 mm] #12 Type AB (Section 2.2)

The length of the screws shall be adequate to insure a constant diameter is engaged throughout the full sample.See Figure 2.

5.2.4.Lead holes shall be pre-drilled, through the full sample depth, using 90% of the root diameter of the screw.

Screw Size Root Diameter 90% Drill Bit

#100.135” - 0.141” 0.122” - 0.127”1/8”

[3.4 mm – 3.6 mm}[3.1 mm – 3.2 mm]

#12 0.157” - 0.164” 0.141” - 0.148”#27

[4.0 mm – 4.2 mm][3.6 mm – 3.8 mm]

Specific Materials may require different pilot holes.Record any variations from this test method in the test report.

5.2.5.A 10 gauge plate (approximately a 0.134” [3.4 mm]hinge) with a 0.330” [8.4 mm]diameter hole shall be used for 1-3/4” [44.5 mm] doorspecimens. A 12 gauge plate (approximately a 0.105” [2.7 mm]hinge) with a 0.260” [6.6 mm]diameter hole shall be used for 1-3/8” [34.9 mm] doorspecimens.

5.2.6.Position the plate on top of the specimen as shown in Figure 2. Insert the screw through the plate hole and into the lead hole, deep enough to engage the entire sample with the constant diameter portion of the threads. Insert the screw with a turning motion so as not to reduce the thread engagement strength of the specimen.

5.3.Horizontal Edge Samples:Cut no more than one (1) 3”[76 mm] specimen from each 15” [381 mm]of pre-fit door rail edge for each test series, and selected from random locations. No specimen shall include portions of stile or optional blocking. Thewidth (Dimension “B”) of the individual rail component shall be measured and recorded in the test results. The specimenshall be prepared for testing as follows:

5.3.1.Where remaining rail or rail/core material is greater than 1”, cut and remove enough material from the interior surface to yield a specimen width of 1" (Dimension “B”).Where rail edge is less than 1”, no additional trimming is required.

5.3.2.#12 Type AB (Section 2.2) shall be used for the test specimen.The length of the screws shall be adequate to insure a constant diameter is engaged throughout the full sample (see Figure 2).

5.3.3.Lead holes shall be pre-drilled, through the full sample depth, using 90% of the root diameter of the screw.

Screw Size Root Diameter 90% Drill Bit

#12 0.157” - 0.164” 0.141” - 0.148” #27

[4.0 mm – 4.2 mm][3.6 mm – 3.8 mm]

Specific Materials may require different pilot holes.Record any variations from this test method in the test report.

5.3.4.A 10 gauge plate (approximately 0.134” [3.4 mm]) with a 0.33” [8.4 mm]diameter hole shall be used.

5.3.5.Position the plate on top of the specimen as shown in Figure 2. Insert the screw through the plate hole and into the lead hole, deep enough to engage the entire sample with the constant diameter portion of the threads. Insert the screw with a turning motion so as not to reduce the thread engagement strength of the specimen.

5.4.Face Samples:Cut no more than one (1) 3”[76.2 mm] specimen from each door facemaintaining at least 15” [381 mm]between samplesfor each test series, and selected from random locations.The thickness (Dimension “C”) of the individual face sample shall be measured and recorded in the test results. The specimen shall be prepared for testing as follows:

5.4.1.Cut and remove enough material from the interior surface to yield a specimen thickness of 1" (Dimension “C”).

5.4.2.Final specimen size to be 3” [76.2 mm] in length x 1.5” [38.1 mm]in width x 1” [25.4 mm] in thicknessfor both 1-3/4” [44.5 mm] thick doors and 1-3/8” [34.9 mm]thick doors.

5.4.3.#12 Type AB (Section 2.2) shall be used for the test specimen.The length of the screws shall be adequate to insure a constant diameter is engaged throughout the full sample (see Figure 2).

5.4.4.Lead holes shall be pre-drilled, through the full sample depth, using 90% of the root diameter of the screw.

Screw Size Root Diameter 90% Drill Bit

#12 0.157” - 0.164”0.141” - 0.148” #27

[4.0 mm – 4.2 mm][3.6 mm – 3.8 mm]

Specific Materials may require different pilot holes.Record any variations from this test method in the test report.

5.4.5.A 10 gauge plate (approximately a 0.134” [3.4 mm]hinge) with a 0.330” [8.4 mm]diameter hole shall be used.

5.4.6.Position the plate on top of the specimen as shown in Figure 2. Insert the screw through the plate hole and into the lead hole, deep enough to engage the entire sample with the constant diameter portion of the threads. Insert the screw with a turning motion so as not to reduce the thread engagement strength of the specimen.

  1. CONDITIONING

The test specimen shall be conditioned to an equilibrium moisture content at 75degrees ±10 degrees F[24 degrees ± 6 degrees C] and 50% ±5%RH.

  1. PROCEDURE
  2. Insert the specimen in the holding fixture of the test apparatus (as shown in Figure 2). Engage the screw head in the load-applying fixture.
  3. Apply the load to the specimen, throughout the test, at a uniform motion rate of 0.10 inches [2.5mm]per minute.
  4. REPORT

Report results on test report attached.The report shall include the following:

  • The average and individual loads required to withdraw the screws from the specimens. (Note: If the screw is broken rather than withdrawn, it shall be noted and the test value shall not be included in the average value reported.)
  • A complete description of the sample specimens testedas well as the composition of all components.
  • Details of any deviations from the materials and/or methods outlined in this procedure.
  • Screw holding capacity for the test series shall be the average of the tested specimens.

FIGURE 1:SAMPLE EXTRACTION & SIZING OF SAMPLES

FIGURE 2:DIAGRAM FOR SCREW WITHDRAWAL


WDMA TM 10-0814(draft)1