ASTM F1832-07(2017)
(Test Method)Standard Test Method for Determining the Force-Draw and Let-Down Curves for Archery Bows
General Information
- Abstract
SIGNIFICANCE AND USE
3.1 This test method establishes the procedure to be used to measure the force necessary to draw an archery bow from brace height to the full draw position, and the holding force necessary to retain the bow string when the bow is let-down from full draw to brace height. The force values taken at increments of draw length are then plotted versus draw length using rectangular coordinates. The resulting curves are known as the force-draw curve and the let-down curve.
3.2 The force-draw curve is used to determine the energy that the limbs of the bow store when it is drawn. The area under the curve between the positions of brace height and full draw can be expressed as stored energy.
3.3 The let-down curve is used to determine the energy required to restrain the bowstring as the bow is let-down from full draw to brace height. The energy represented by the area under the curve can be subtracted from the stored energy in order to establish the static hysteresis of the bow system.
SCOPE
1.1 This test method covers the procedure to be used to determine the force-draw and let-down curves for archery bows.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
- Status
- Published
- Publication Date
- 30-Nov-2017
- Technical Committee
- F08 - Sports Equipment, Playing Surfaces, and Facilities
- Drafting Committee
- F08.16 - Archery Products
Overview
ASTM F1832-07(2017): Standard Test Method for Determining the Force-Draw and Let-Down Curves for Archery Bows outlines the standardized procedure for measuring the force required to draw and then release (let-down) an archery bow from brace height to full draw and back. Developed by ASTM International, this standard offers a repeatable, reliable method for quantifying bow performance, ensuring quality control, accurate product comparison, and enhanced safety in archery bow manufacturing and testing.
This test method is applicable to both compound and non-compound (traditional) bows and is an important reference for physical testing laboratories, manufacturers, and product certifiers. The measurements obtained are typically used to evaluate stored energy, assess static hysteresis, and compare the mechanical efficiency of various bow designs.
Key Topics
- Force-Draw and Let-Down Curves
- The force-draw curve plots the force needed to draw the bowstring as the draw length increases, providing insight into the energy storage characteristics of the bow.
- The let-down curve measures the force required to retain the bowstring as it returns from full draw to brace height, useful for assessing the energy release and system hysteresis.
- Stored Energy and Static Hysteresis
- Stored energy is determined by measuring the area under the force-draw curve between brace height and full draw, typically expressed in foot-pounds or joules.
- Static hysteresis is calculated by subtracting the area under the let-down curve from the stored energy, indicating energy lost due to internal resistance and friction in the bow.
- Instrumentation and Procedure
- Use of precise force-draw machines and force-reading devices (e.g. load cells) capable of reliable and repeatable readings.
- Standardized draw length measurement, typically following the Archery Trade Association (ATA) draw length specification.
- Incremental data collection for both draw and let-down phases to generate accurate curves for analysis.
Applications
- Bow Design and Manufacturing
- Enables manufacturers to optimize bow limb geometry, materials, and cam systems (in compound bows) for maximum performance and user comfort.
- Provides benchmark data for product development and quality assurance processes.
- Product Comparison and Certification
- Offers a standardized approach for comparing bows across different brands, models, or technologies on key mechanical attributes such as peak draw force, let-off, and energy efficiency.
- Research and Development
- Facilitates biomechanical and engineering studies on bow ergonomics, arrow flight consistency, and the impact of design changes.
- End-User Safety and Performance
- Helps ensure that bows meet specific performance and safety criteria prior to market release, supporting archers’ needs for reliable and consistent equipment.
Related Standards
- ASTM F2212 - Standard Terminology Relating to Archery
- ASTM F1359 - Standard Test Method for Determination of the Mechanical Properties of Archery Bows
- ATA Standards - Specifications for draw length and other archery equipment dimensions
- International guidelines referenced by the WTO Technical Barriers to Trade (TBT) Committee
By adhering to ASTM F1832-07(2017), manufacturers and testing laboratories ensure consistent evaluation of archery bows, fostering international trade, consumer safety, and product innovation in the archery industry. For additional guidance, refer to related ASTM and ATA standards to address terminology, test conditions, and additional performance aspects.
Relations
- Effective Date
- 01-Dec-2017
Frequently Asked Questions
ASTM F1832-07(2017) is a standard published by ASTM International. Its full title is "Standard Test Method for Determining the Force-Draw and Let-Down Curves for Archery Bows". This standard covers: SIGNIFICANCE AND USE 3.1 This test method establishes the procedure to be used to measure the force necessary to draw an archery bow from brace height to the full draw position, and the holding force necessary to retain the bow string when the bow is let-down from full draw to brace height. The force values taken at increments of draw length are then plotted versus draw length using rectangular coordinates. The resulting curves are known as the force-draw curve and the let-down curve. 3.2 The force-draw curve is used to determine the energy that the limbs of the bow store when it is drawn. The area under the curve between the positions of brace height and full draw can be expressed as stored energy. 3.3 The let-down curve is used to determine the energy required to restrain the bowstring as the bow is let-down from full draw to brace height. The energy represented by the area under the curve can be subtracted from the stored energy in order to establish the static hysteresis of the bow system. SCOPE 1.1 This test method covers the procedure to be used to determine the force-draw and let-down curves for archery bows. 1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
SIGNIFICANCE AND USE 3.1 This test method establishes the procedure to be used to measure the force necessary to draw an archery bow from brace height to the full draw position, and the holding force necessary to retain the bow string when the bow is let-down from full draw to brace height. The force values taken at increments of draw length are then plotted versus draw length using rectangular coordinates. The resulting curves are known as the force-draw curve and the let-down curve. 3.2 The force-draw curve is used to determine the energy that the limbs of the bow store when it is drawn. The area under the curve between the positions of brace height and full draw can be expressed as stored energy. 3.3 The let-down curve is used to determine the energy required to restrain the bowstring as the bow is let-down from full draw to brace height. The energy represented by the area under the curve can be subtracted from the stored energy in order to establish the static hysteresis of the bow system. SCOPE 1.1 This test method covers the procedure to be used to determine the force-draw and let-down curves for archery bows. 1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only. 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use. 1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
ASTM F1832-07(2017) is classified under the following ICS (International Classification for Standards) categories: 97.220.40 - Outdoor and water sports equipment. The ICS classification helps identify the subject area and facilitates finding related standards.
ASTM F1832-07(2017) has the following relationships with other standards: It is inter standard links to ASTM F1832-07(2011). Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
ASTM F1832-07(2017) is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: F1832 − 07 (Reapproved 2017) An American National Standard
Standard Test Method for
Determining the Force-Draw and Let-Down Curves for
Archery Bows
This standard is issued under the fixed designation F1832; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2.1.3.1 Discussion—This secondary control system can be
composed of cam, levers, cables, or other elements, and
1.1 This test method covers the procedure to be used to
combinations thereof. The dual control system permits great
determine the force-draw and let-down curves for archery
versatility in the design of the force-draw characteristic, and
bows.
simplifies the inclusion of let-off. In general, it is normal for
1.2 The values stated in inch-pound units are to be regarded
compound bows to have greater stored energy than conven-
as the standard. The SI units given in parentheses are for
tional bows for a given level of peak or maximum draw weight.
information only.
2.1.4 draw, v—to move the shooting string of a bow from
1.3 This standard does not purport to address all of the
the rest or braced position toward the full drawn position by
safety concerns, if any, associated with its use. It is the
applying force to said string.
responsibility of the user of this standard to establish appro-
2.1.4.1 Discussion—Such action causes the limbs of the
priate safety, health, and environmental practices and deter-
bow to bend and store energy. Moving the string from brace
mine the applicability of regulatory limitations prior to use.
height to the full draw position corresponds to the draw stroke
1.4 This international standard was developed in accor-
of a bow.
dance with internationally recognized principles on standard-
2.1.5 draw cycle, n—combination of the draw-stroke and
ization established in the Decision on Principles for the
the let-down stroke, resulting in a full cycle from brace height
Development of International Standards, Guides and Recom-
to full draw and return to brace height.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2.1.6 draw-stroke, n—distance in inches (millimeters) from
brace height to full draw.
2. Terminology
2.1.7 force-draw curve, n—curve that is plotted using the
2.1 Definitions of Terms Specific to This Standard:
force readings, taken at incremental values of draw length
2.1.1 ATA (archery trade association) draw length,
when drawing the bow, as the ordinate and the corresponding
n—perpendicular distance from the point where the shooting
draw length as abscissa.
string of the bow contacts bottom of the nock slot of the arrow,
2.1.8 full draw, n—position assumed by the bowstring when
to a vertical line through the pivot or low point of the hand grip
3 the bow is drawn to a draw length corresponding to that from
(draw length pivot point), plus a standard dimension of 1 ⁄4 in.
which it will be released for the shot.
(44.5 mm).
2.1.8.1 Discussion—For most standard test purposes full
2.1.2 brace height, n—dimension in inches (millimetres),
draw is specified as 30 in. (762 mm) ATA draw length for
from the grip pivot point (low point) of the grip to the nearest
compound bows, and 28 in. (711.2 mm) ATA draw length for
side of the bowstring, measured perpendicular to the
non-compound bows, but it can take any assigned value.
bowstring, with the bow strung and in the undrawn condition.
2.1.9 let-down curve, n—curve that is plotted using the force
2.1.3 compound bow, n—type of bow that imposes a sec-
readings, taken at incremental values of draw length when
ondarysystemofcontroloftheforce-drawcharacteristiconthe
relaxing the bow, as the ordinate and the corresponding draw
usual limb geometry control system of the conventional bow.
length as abscissa.
2.1.10 let-off, n—difference between the peak or maximum
1 draw force reached during the draw stroke of a bow, and the
This test method is under the jurisdiction of ASTM Committee F08 onSports
Equipment, Playing Surfaces, and Facilities and is the direct responsibility of lowest level of draw force reached subsequent to that peak.
Subcommittee F08.16 on Archery Products.
2.1.10.1 Discussion—Quantitatively, it is most frequently
Current edition approved Dec. 1, 2017. Published December 2017. Originally
expressed as a percentage of the peak force and is then referred
approved in 1997. Last previous edition approved in 2011 as F1832 – 07 (2011).
DOI: 10.1520/F1832-07R17. to as percent of let-off.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F1832 − 07 (2017)
2.1.11 non-compound bow, n—bow constructed in the tra- used to draw the bowstring shall be capable of a smooth and
ditional manner, having two flexing limbs extending outwardly steady movement, and must maintain continuous unrelaxed
in opposite directions from a handle.
force so that no hysteresis effect is experienced.
2.1.11.1 Discussion—A single shooting string of a length
4.2 Force-Reading Device—A scale or load cell shall be
shorter than the bow, connects the extreme ends of the limbs
interposed between the bowstring and the cable or rod used to
causing them to assume a pre-stressed flexed condition. Draw-
draw the bowstring so that the force reading is direct and not
ing the bow causes additional bending and stressing of the
contaminated in any way. The force measuring device shall be
limbs, storing the energy necessary to propel the arrow. Control
capable of weighing to 0.25 lbf (1.12 N). A spring scale with
of the force-draw characteristic of the bow is exercised entirely
adequate resolution may be capable of measuring the drawing
by the static and dynamic geometry of the flexing limbs and the
force for conventional bows but will provide questionable
bowstring.
values when used for compound bows with precipitous let-off.
2.1.12 peak draw force, n—maximum force reached when
drawing a bow. 4.3 Draw Length Scale—A
...