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Home  >>  Products  >>  Impact/Flexibility  >>  Universal Impact Tester

Universal Impact Tester

Model # 172RF

Universal Impact Tester Model #172
Model No. IM-172RF





Basic Testers - The basic impact tester is made up of two major assemblies, the base and the guide tube. The black anodized solid aluminum base is 1.5" thick, 10" wide, 12" deep and has a sturdy arm for holding the guide tube. It is also fitted with: Leveling Screws, Die cavity, Circular level, Tube Clamp & Two test panel magnets.

The anodized aluminum gravity guide tube is 48" high, 1.25" I.D. and fitted with: Height scale-Inches/Centimeters & Height clamp







The experience of many years has taught that the bending and stretching of the metal base on which a coating was applied provided valuable information on the elastic and adhesive characteristics of the coating. Numerous types of instruments have been used: powered elongation testers, cylindrical or conical mandrels, manual or powered indenters and falling weight indenters.

The falling weight indenters are normally most severe due to the "shock" nature of the test. Many different falling weight indenters are now in use and it is the design purpose of the new UNIVERSAL IMPACT TESTER, MODEL 172RF, to provide a range of operating capability that matches or exceeds most of these existing instruments. In addition, MODEL 172RF, with selected auxiliaries, exceeds specification ASTM D 2794.

Impact Tester Close Up
Shown with magnets that hold your substrate to the impact tester.
Impact Teste with Allen Wrench
Allen wrench (as shown) can be used to support the
combination weight/indenter of the impact tester to make removing test panel
simple and convenient.


Technical Data

Technical Data
Spherical Segment End Base Diameter Segment Radius Segment Evaluation % Area Increase
1 A 0.375 0.194 0.146 60
2 A 0.375 0.208 0.119 40
3 A 0.375 0.252 0.084 20
4 A 0.375 0.326 0.059 10
5 B 0.375 0.440 0.042 5
6 B 0.375 0.676 0.027 2
7 B 0.375 0.947 0.019 1
8 B 0.375 1.332 0.013 .5



Operating procedure for the 172RF impact testers are essentially the same for all die, indenter punch and weight or combined ball weight-indenter punch combinations except for the GE impacter.

Insure that the impact tester is level and that the desired die, indenter punch and weight or combined weight-indenter punch are in place. It may be convenient to set the guide tube clamp at a specified height if a particular test series is to receive the same impact energy. Normal procedure is to place the test panel between the impact tester indenter punch and the die with the coating facing downward against the die. (Some investigators have gained important information on coating properties by placing the panel in the apparatus with the coating facing upward and in contact with the indenter punch). With the test panel in place, raise the weight or combined weight indenter punch of the impact tester to a predetermined level and release. Remove the test panel and inspect the condition of the coating. The test may then be repeated at the same drop level to confirm the initial reading or repeated at a different drop level.

Following each impact test, the coating condition should be recorded along with the inch-pounds or meter-kilograms of the drop. It is also recommended that coating thickness be measured and recorded as well as the curing schedule and other possible influencing factors. Inch-pounds of drop is determined by subtracting the height reading, if not zero, by adjustment of the guide tube in the base arm, of the lifting rod or other index mark when the drop member is at rest on the test specimen from the drop height at the same reference point and multiplying this value by the pound weight of the drop element.
G.E. Impact-Flexibility Procedure
Operating procedure for the GE Impact Tester: Remove the die from its cavity in the base unit and install between the magnets, the aluminum plate with the top rubber anvil held in place with two strong rubber bands insuring that the bands are in the grooves of the plate so that the plate seats firmly on the base. This rubber anvil has a 60 Shore hardness and should be replaced if worn or damaged. Install the GE impacter in the guide tube.

With an uncoated panel in place on the rubber anvil, determine the height of drop for each end of the impacter to show on the panel slight evenly spaced segment marks of the impacter circumference. The heights so determined will always be used. Place the coated panel to be tested face down against the rubber anvil and drop the impacter from the above determined height. Remove the panel from the impact tester and inspect the coating. Record the maximum percent area increase accommodated by the coating without cracking or other failure, from the table on the preceding page.


Assembly Instructions

  1. Secure the three leveling screws on the bottom of the base.
  2. Temporarily secure gravity tube to the base using the supplied allen wrench.
  3. Place die in die cavity of base.
  4. Tilt impact tester on side and at top of tube insert combined weight& ball or indenter punch & separate weight.
  5. While instrument is tilted on its side, place ball handle in indicator guide and secure assembly to combined weight & ball or separate weight. Be sure to place white indicator facing height scale.
  6. Hold indicator guide handle and slowly stand impact tester upright (if using indenter punch & separate weight combination let indenter punch slowly slide down the gravity tube as you stand
    the impact tester upright) then lower handle with weight down to the base.
  7. Slide height clamp over top of gravity tube and secure with knob handle.
  8. Level the impact tester by adjusting the three bottom leveling screws on the base until level bubble is centered.
  9. Lift handle and place panel on top of die and secure panel by use of magnets. If sample is non-magnetic it may be possible to use supplied magnet keepers to secure sample.
  10. Lift handle and place the square calibration block on top of test panel beneath the indenter. Lower handle so the indenter is resting on the 1" gauge block.
  11. Loosen gravity tube with allen wrench and adjust gravity tube up or down and align the indicator guide up with the one inch mark on the height scale of the gravity tube. Tighten gravity tube.
  12. Hold handle firmly and carefully remove the gage block. Slowly bring the handle down allowing the ball to rest on the panel surface, adjust panel as necessary.
  13. If you are testing multiple panels at a fixed height drop, release height clamp and adjust to designated height and secure.
  14. Assembly of the Gardco IM-172RF is complete.
  15. Always wear safety goggles during the impact tester operation.


Method of Use


Coatings to be tested are applied to cleaned thin metal panels (suitable panels are available from the Paul N. Gardner Company.) After the coating to be tested is properly cured and ready for test, the test panel is placed on the selected supporting die and magnets of the impact tester, or for the GE evaluation, on the flexible anvil.

The selected indenter with associated weight or the combined indenter weight is placed in the tube so that it rests on the test panel. The guide tube is then adjusted in the base so that the scale registers zero at the lifting handle or mark and/or the position of such lifting member while at rest. The weight or combined weight indenter is then raised to the desired height, noted and released.

The test panel is inspected, and depending on results, the test may be repeated by releasing the weight or the combined weight indenter at a higher or lower elevation. (When using the GE Flexibility Test Impacter the usual practice is to use a fixed height drop, as is covered under "Procedure" below). Coating failure is determined when cracks first appear in the coating with the minimum inch-pounds of falling weight. Such failure cracks may be made more visible by the application to the test area of a copper sulfate solution (CuSO4).



Universal Impact Tester Kit

(A) IM-172-1 - 2 lb., 1/2" Dropping Wt. (H) IM-172-9 - Die Original 5/8" 0.685" (O) IM-172-GE/2 - Fixture Plate
(B) IM-172-3 - 2 lb., 5/8" Dropping Wt. (I) IM-172-2 - ASTM 0.640" Die (P) IM-172-GE/3 - Rubber Anvil Pad
(C) IM-172-71 - 2 lb., Extnsn Wt. male/female (J) IM-172-45 - 14.5MM Proportional Die (Q) IM-172RF-912 - 3" Elevation Block
(D) IM-172-60 - ASTM 2 lb. Dropping Wt. (K) IM-172-4 - Accompanying Die (R) IM-172RF-911 - 1-1/2" Elevtn Block
(E) IM-172-31 - ASTM 5/8" Ball Indntr Punch (L) IM-172-0 - Blind Plg 40mm Rad.x1" Deep (S) IM-172-9303 - V-Block Pipe Center
(F) IM-172-11 - ASTM 1/2" Ball Indntr Punch (M) IM-172-GE/1 - Flexibility Impacter
(G) IM-172-12 - ASTM 0.125" Rad. 20° Indntr Pch (N) Carrying Case for Weights & Dies


Specification References

  • ASTM D2794 "Resistance of Organic Coatings to the Effects of Rapid Deformation - Impact". MIL-P-85582C; MIL-P-23377G; MIL-C-85285A; MIL-E-24763A (SH); NCAA 11-10 (11-6, 11-16, AND X-1); ECCA
  • ASTM D4226 "Impact Resistance of PVC Building Products"
  • Meets ASTM G14 with optional accessories - Call for details
  • General Electric Company PLI-100 "Modified Gardner Impact Strength". 1975
  • Federal Highway Administration FP-74 "Standard Specifications for the Construction of Roads and Bridges on Federal Projects" Section 633.06 Traffic Control Signs- Impact Resistance.
  • Model 172RF meets Proposed Revision of TT-P-2756A, Polyurethane Coating: Self-Priming Topcoat, Low Volatile Organic Compounds (VOC).
  • ASTM D6905 "Standard Test Method For Impact Flexibility Of Organic Coatings"
  • ASTM D5420 "Standard Test Method for Impact Resistance of Flat, Rigid Plastic Specimens by means of a Falling Dart"

Universal Impact Tester Diagram
Weight Tolerances above ± 5%

ASTM Method D2794, which is now also used in place of Federal Test Method Standard No. 141C, 6226 calls for a 0.64" diameter die which may be used with either a separate 0.500" or a 0.625" hemispherical head indenter. The ASTM method specifies that a separate weight (IM-172-60) be used to impact against the indenter punch. Normally, a two pound weight will satisfy most test conditions.

Range of the test equipment may be greatly extended by the use of an auxiliary drop weight. The two pound auxiliary weight may be secured to and used with the two pound separate drop weight.Many operators have found it more convenient to replace the separate weight and indenter punch with a combined single unit. The two pound combined units are available with hemispherical tip diameters of .500" and 0.625". The one kilogram combined unit has a tip diameter of 20 mm.

The combined weight indenter punch units have been found to provide a somewhat more severe test condition than the separate weight and indenter punch. This is due to the separate stationary indenter absorbing a small amount of the drop weight energy.

GE Flexibility Tester

Some of the Specifications That Call For the Use of the GE Impact-Flexibility Test are MIL-P-85582A, MIL-P-23377C, MIL C85285A and ASTM D6905-03 

The Universal lmpact Tester, Model 172RF, also accommodates the GE Impact Flexibilily test method. The GE impacter weights 3.6 pounds and has formed on each end four convex spherical segments which are of different radii and extensions.


Modified IM-172RF-801

Universal Impact Tester IM-172-801

The modified 172RF impact tester meets ASTM D5420 (geometry GA, GB, GC, GD and GE) die configuration. The dies for the different geometries are shown above. The indenter punch would be determined by which geometry you are going to use. The GD and GE uses a IM-172-11 Indenter Punch, and the GA, GB or GC geometry uses the IM-172-31 Indenter Punch. (IM-172-60 2lb weight is required).

The base on the new IM-172RF-801 impact tester has a special 3.25” diameter die cavity to accommodate the IM-172-832 (31.75mm) and IM-172-876 (76mm) die (Optional Accessories). The IM-172RF-801 can accommodate all the standard size dies when used with the IM-172-807 standard size die adaptor.

The new IM-172RF-801 impact tester consists of the modified base and gravity tube. The operation of this instrument is the same as the regular IM-172RF impact tester and all die and accessories are sold separately.






Prices subject to change    Prices listed in US dollars for domestic shipments within US, Canada, & Mexico only    Export orders require quotations - click here for a quote     For more info call us 1-800-762-2478 or 954-946-9454.
Item Number Item Prices
All accessories are sold separately but the following are needed to make a complete system: Model 172 Impact Tester (base & gravity tube), Indenter (punch & falling weight or combined ball & weight), Receiving Die
IM-172RF Model 172 Basic Impact Tester $1,597.05
IM-172-0 Blind Plug 40MM Radius X 1" Deep 247.80
IM-172-1 Comb. 1/2" Ball & 2 lbs WT Indenter 117.60
IM-172-11 ASTM 1/2" Ball Indenter Punch (GD and GE geometry) 141.75
IM-172-12 ASTM D4226 0.125" Radius 20° Indenter Punch 485.10
IM-172-2 Accompanying Die, ASTM 0.640" 109.20
IM-172-3 Combined 5/8" Ball & 2 lb WT Indenter 117.60
IM-172-31 ASTM 5/8" Ball Indenter Punch (GA, GB and GC geometry) 159.95
IM-172-4 Accompanying Die 109.20
IM-172-5 20MM Ball and 1kg weight combined 156.45
IM-172-60 ASTM 2 lb Dropping WT For Indenter Punch 125.00
IM-172-71 Extension Weight, 2 lbs., Male/Female 125.00
IM-172-8 Additional Screw-on WT,1 KG 114.45
IM-172-9 Die Original for 5/8" 0.685" 109.20
IM-172RF-R01 Gravity Tube Replacement Only 468.30
IM-172-GE GE Impact Test Adapter Complete, ASTM D 6905 2,601.90
IM-172-GE/1 GE Indenter Only 2,150.40
IM-172-GE/2 GE Fixture Plate Only 413.70
IM-172-GE/3 GE Rubber Anvil Pad Replacement 46.20
IM-172RF-911 1-1/2" Elevation Block 156.45
IM-172RF-912 3" Elevation Block 176.40
IM-172-G14 Complete Accessory Kit for G14 Method 784.35
IM-172-G14/1 ASTM G14 Combined 3 lb Weight, 5/8" Dia. Ball 264.60
IM-172-G14/2 ASTM G14 V-Block Attachment w/Hardware 381.15
IM-172-G14/3 Clamps, High Torque Stainless (Pair) 13.65
Modified IM-172RF
IM-172RF-801 Modified Base with Special Die Cavity 1,873.20
Accessories for IM-172RF-801 only
IM-172-807 Die Adapter for Standard Die 286.65
IM-172-832 31.75 mm Die (GB geometry) 286.65
IM-172-876 76 mm Die (GA & GD geometry) 286.65
Special dies, weights & indenters made upon request to your specifications.

¹Warning: Damage will result if receiving die or blank plate such as IM-172-GE/2 (RUBBER ANVIL PAD) is not in place while the instrument is in use.

Caution: The operation of this instrument involves high energy impact. Eyes should be protected with safety glasses. Fingers and hands should be kept clear of the impact area.


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