ASTM F959 Technical Data

 

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This specification covers the requirements for compressible-washer-type direct tension indicators, (DTIs) capable of indicating the achievement of a specified minimum bolt tension in a structural bolt.

Chemical Requirements

 Composition,%
ElementHeat Analysis Product Analysis 
 Type 1 SeriesType 3 SeriesAType 1 SeriesType 3 SeriesA
Carbon0.30-0.55 0.27-0.58 
Manganese0.50-0.90 0.47-0.93 
Phosphorus, Max0.040.0400.0480.045
Sulfur, Max0.0450.0500.0530.055
Silicon0.15-0.350.15-0.350.13-0.370.13-0.37
Chromium 0.45-0.65 0.42-0.68
Nickel 0.25-0.45 0.22-0.48
Copper 0.25-0.45 0.22-0.48

 

AType 3 DTI's are also permitted to be manufactured from any of the Type 3 steels in the chemical composition sections of Specifications A325 and F436 or ASTM A325M and A436M.

Acceptable Range of Compression Loads

DTI Size (Nominal Diameter, in.)Compression Load Range in Thousands of Pounds, (kips)
 Types 325 and 325-3Types 490 and 490-3
1⁄212-1415-18
5⁄819-2324-29
3⁄428-3435-42
7⁄839-4749-59
151-6164-77
11⁄856-6780-96
11⁄471-85102-122
13⁄885-102121-145
11⁄2103-124148-178
DTI Size (Nominal Diameter,   mm)Compression Load Range for Metric Series in Kilonewtons, (kN)
 Types 8.8-1 and 8.8-3Types 10.9-1 and 10.9-3
M1691-109114-131
M20142-170179-206
M22176-211221-254
M24205-246257-296
M27267-320334-384
M30326-391408-469
M36475-570595-684