Flat Washer Chart
OPTIMUM FLAT WASHER CONFIGURATION CHART FOR USE WITH SQUIRTER® DTI'S
Non-standard holes in outer plies must be covered by an appropriate ASTM
F436 flat washer (see RCSC Table 6.1).
If an ASTM F436 washer is required under a Squirter® DTI, a special flat
washer should be procured for optimum squirt performance. While standard
ASTM F436 washers are acceptable per specification, their use sacrifices
some of the benefits of a Squirter® DTI. See below for details.
| Detail C of Figure 1.2 illustrates problematic use of standard ASTM F436 washers on top of DTI bumps, eccencentricity due to sloppy washer inner diameters, may result in partial compression of DTI bumps. |  |
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| Flat Washer Recommendations for Use With Squirter® DTI's | ||||||||
| Optimum Washer (See Graphic 1.1) |
Bolt Type | Bolt/Squirter DTI Size | ||||||
| 3/4" | 7/8" | 1" | 1-1/8" | 1-1/4" | 1-3/8" | 1-1/2" | ||
| A flat washer under nut |
A325 or A490 | 3/4" F436 | 7/8" F436 | 1" F436 | 1-1/8" F436 | SAE 1-1/8" | SAE 1-1/4" | SAE 1-3/8" |
| B flat washer over OS/SS |
A325 | 3/4" USS | 7/8" USS | 1" USS | 118UH | 114UH | 138UH | 112UH |
| A490 | 3/4" USS | 7/8" USS | 1" USS | 118USPTKH | 114USPTKH | 138USPTKH | 112USPTKH | |
Washer B (yellow washer per 1.1 and table) is only recommended for oversized and short-slotted hole configurations.
| Various Flat Washer Dimensions1 | |||
| Size/Type | ID | OD | Thickness |
|---|---|---|---|
| 3/4" F436 | 13/16" | 1-15/32" | .122-.177 |
| 7/8" F436 | 15/16" | 1-3/4" | .136-.177 |
| 1" F436 | 1-1/16" | 2 | .136-.177 |
| 1-1/8" F436 | 1-3/16" | 2-1/4" | .136-.177 |
| 1-1/4" F436 | 1-3/8" | 2-1/2" | .136-.177 |
| 1-3/8" F436 | 1-1/2" | 2-3/4" | .136-.177 |
| 1-1/2" F436 | 1-5/8" | 3" | .136-.177 |
 F436 washers have a tight ID (+1/16") up to and including 1-1/8"
bolt size and sloppy ID's (+1/8") 1-1/4" up to 1-1/2" . |
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| 3/4" USS | 13/16" | 2" | .122-.177 |
| 7/8" USS | 15/16" | 2-1/4" | .136-.192 |
| 1" USS | 1-1/16" | 2-1/.2" | .136-.192 |
| USS washers have a tighter ID and an OD sufficiently
bigger than the DTI up to and including 1". USS flat
washers are available both hardened and
unhardened. Use ONLY hardened. |
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| 1-1/4" SAE | 1-3/8" | 2-1/2" | .136-.165 |
| 1-3/8" SAE | 1-1/2" | 2-3/4" | .153-.180 |
| 1-1/2" SAE | 1-5/8" | 3" | .153-.213 |
| SAE washers have a tighter ID than ASTM F436
washers, and therefore fit better. SAE washers are
available both hardened and unhardened.
Use ONLY hardened SAE washers over DTI bumps. |
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| Applied Bolting Special USS washers | |||
| 118UH | 1-3/16" | 2-3/4" | .136 min |
| 114UH | 1-5/16" | 3" | .136 min |
| 138UH | 1-7/16" | 3-1/4" | .136 min |
| 112UH | 1-9/16" | 3-1/2" | .136 min |
| 118USPTKH | 1-3/16" | 2-3/4" | 5/16" |
| 114USPTKH | 1-5/16" | 3" | 5/16" |
| 138USPTKH | 1-7/16" | 3-1/4" | 5/16" |
| 112USPTKH | 1-9/16" | 3-1/2" | 5/16" |
| 1 F436 Dimensions per ASTM Specifications, USS and SAE dimensions per ANSI B18.22.1 | |||
| UH and USPTKH washers are special washers for
use under Squirter® DTI's wherever oversized and
short-slotted holes are encountered 1-1/8" up to 1-1/2". These washers
have the OD of a USS washer with a tight ID
(1/16" over nominal bolt size).
Call Applied Bolting for availability. |
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| ASTM F 959 DTI Dimensions | |||
| 3/4" A325 | .790" | 1.625" | .126-.230 |
| 7/8" A325 | .921" | 1.875" | .142-.240 |
| 1" A325 | 1.048" | 2.000" | .158-.270 |
| 1-1/8" A325 | 1.179" | 2.250" | .158-.270 |
| 1-1/4" A325 | 1.311" | 2.500" | .158-.270 |
| 1-3/8" A325 | 1.442" | 2.750" | .158-.270 |
| 1-1/2" A325 | 1.573" | 3.000" | .158-.270 |
| 3/4" A490 | .790" | 1.750 | .126-.230 |
| 7/8" A490 | .921" | 2.000 | .142-.240 |
| 1" A490 | 1.048" | 2.250 | .158-.270 |
| 1-1/8" A490 | 1.179" | 2.500 | .158-.270 |
| 1-1/4" A490 | 1.311" | 2.750 | .158-.270 |
| 1-3/8" A490 | 1.442" | 3.000 | .158-.270 |
| 1-1/2" A490 | 1.573" | 3.250 | .158-.270 |
| ASTM F959 DTI Dimensions. |
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| Nut side installation illustrated, for other configurations please call Applied Bolting. |
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