ABSTRACT
Presenting time-tested standard as well as reliable emerging knowledge on threaded fasteners and joints, this book covers how to select parts and materials, predict behavior, control assembly processes, and solve on-the-job problems. It examines key issues affecting bolting in the automotive, pressure vessel, petrochemical, aerospace, and structura
TABLE OF CONTENTS
chapter |3 pages
It is possible to have hydrogen released
of these data are shown in Tables 13 and 14.
chapter |2 pages
of Alloys in Nitric Acid Solutions• at 50°C
of titanium fasteners with aluminum joints in wide-body aircraft. The superior corrosion of the titanium causes rapid attack by galvanic and exfoliation (a form of crevice)
chapter |4 pages
of six conditions that included
of friction of the bolt thread and bolt head contact of a lubricant is a function of
chapter |5 pages
Load Retention Performance of Various Locking Devices
5.2. Thread Sealing 5.2.1. Sealant Types
chapter |2 pages
of application of various finishes consult
of applying a thin metal coating onto of familiar items would include small appliance items such as toasters + 2e (electrons)__,. Ni (deposited nickel) + 2e H(hydrogen) + 20H-
chapter 6|1 pages
2.4. Mechanical, Chemical, and Electrochemical Surface Treatment Prior to Electroplating Mechanical
of increased absorption of hydrogen by materials. Less of a 10 s maximum of either nitric, sulfuric, or fluoboric acid for activation of bolts
chapter 4|2 pages
6.3. Processing Effects
of the part, it can cause sudden failure after of the part so merits.
chapter |3 pages
VARIATION IN SAMPLING
of a tolerance for some specific reason (engineering fit preferences,
chapter |13 pages
SOURCE MARKING: MANUFACTURER'S IDENTIFICATION
source-unless, of course, the product configuration or hardness precludes rea-
chapter 8|1 pages
BENDING STRESS
stress-bending. Bending can be introduced into the grip of a I= second moment of area (in.mm
chapter |1 pages
of engagement is one, are then selected until the basic design rule
Cl = dilation strength reduction factor of s/D between 1.4 and 1.9 and is plotted in Figure 7. Note of s/D greater than 1.9.
chapter 206|2 pages
Marbacher of Group A2 and A4 Alloys in Percent of Yield Strength at
7 .2. Estimating Screw Diameter
chapter |1 pages
of torque wrench (operator errors)
8.2.1. Tightening Torque Calculation for Metric Fasteners 8.2.2. Original Formula for Torque of the bolt and/or nut. The torque can be calculated very accurately. 2 + +
chapter |3 pages
= fastening system deflection = =
of preload lost due to a give relaxation R is equal to RldL.., + 0.001 2
chapter |6 pages
of the Belleville (in.)
4.1.6. Installation Procedure of proper and improper ways to install two Belleville springs in
chapter |3 pages
Performance Standards for Nonmetallic Resistant Element Type Prevailing
thread Strength grade of screw diameter on-torque, torque, torque, thread SAE SAE ASTM maximum minimum
chapter |1 pages
= p. Then
-kb kbb It might therefore seem that the gasket should be chosen to be very
chapter 3|2 pages
5. Calculation of Flange Stresses
/LfB of the flange. Factors f, of the adjustments described of differential equations to a "cookbook"
chapter |4 pages
of Amand Am
g,/gwhich would indicate an + gfor integral type flanges when f 1 (in.). of welds (in.), equal to or t.,
chapter |6 pages
(a) (b)
It is a little easier to get a counterbored surface parallel to the plate surface than to get
chapter |2 pages
of both ASD and LRFD specifies that standard
of design lead to comparable of multiple loads
chapter |4 pages
if slip into bearing
Applied Tension of the threaded part of the bolt (As.). Because different dimensional properties of the bolt (body
chapter 5|3 pages
2. Slip Considerations at Factored Load Levels
5.3. Modifications to Accommodate Tensile Loads on
chapter |7 pages
of fastener assemblies under the real conditions that
of fastener assemblies is not specified in great detail. However,
chapter |1 pages
"grow" a little between passes, for example, even when there is no tem-
5/8-18 1 3/4 Grade 8 bolts with a torque of 150 lb-ft. This stretched the bolt 0.0015 in. of only 0.001 in. We reapplied
chapter |7 pages
of a bolted joint in which the joint members are rep-
of force on this joint instead of 20,000. Doubling the compressive force
chapter 3|19 pages
3. What the Data Reveals
It is suggested that this is true in general, but one should be careful to extrapolate data of this
chapter 7|5 pages
STRESS RELIEF THROUGH MJTs of the main bolt creates a bending
8.1. Installation frequently-do not of the main bolt/stud and the main thread of the tensioner are
chapter |6 pages
of Assembly 565
friction friction (50 "lo) of the threads: The faces of Unified or metric threads are angled at
chapter 2|5 pages
BOLT TENSION MEASUREMENT
M (for a specified bolt, tension), that provides the most realistic parameter for
chapter |1 pages
of bolting alloys. Recalibration of the tension measuring is possible, but often
4.1. C Micrometers 4.2. Depth Micrometers
chapter |8 pages
of the fastener is
of a given fastener is by testing. The test fixture must resemble the actual of the of Figure 2, the fastener spring rate is
chapter |1 pages
of "wrong answer" it gets when it measures
of course, as the temperature goes up or down. The of linear expansion of steel might be 6.48 10-in./(in.tF) or 11.7 10-mm/ (mmtC) (the coefficient varies somewhat with alloy content, etc.).
chapter |3 pages
in-but of
of the change in of the fastener, it is important that this gap be controlled. We don't car what it is. We
chapter |1 pages
"worse" was a big improvement over 4:1 and was acceptable on all but the most stubborn
9.1. Description of 1-10 (Fig. 12), were used; seven were 5/16"-18 SAE Grade 2 (locations 1, 2, 5,
chapter 9|1 pages
2. Procedure
of each bolt by tensile testing each fastener in the joint. of the spring rates are given in Table 1 (see Section 9.3). of turn, until the desired bolt stretch is reached. of 2000 lb. ''fresh'' joints using fasteners with machined ends. Then use ultrasonic mea-
chapter |1 pages
of 2000 lb
of the torque control of 70 bolts were specially machined at both ends in preparation for the ultrasonic measurements
chapter 4|3 pages
1. Basic Assumptions
if subsequent load and environmental of the 48-62% range established earlier-i.e., our target, in-service bolt
chapter 2|2 pages
CONSTRUCTING THE BASIC JOINT DIAGRAM
of this action on a single of Figure 1. This diagram looks much like a stress-strain of the force-deflection line reflects the stiffness of the bolt "spring,"
chapter 8|1 pages
NONLINEAR BEHAVIOR OF BOLTED JOINTS
of the joint apart. This situation is illustrated in Figure 17. The resulting joint
chapter 4|1 pages
2. Behavior of Joints After Tightening Bolts to Yield
of its uniaxial of strength between the as- of the joint of locking methods is warranted. A change in design of the joint may be of locking bolts are available as well as locking nuts. of the loosening forces [4]. 5. EFFECT OF MANUFACTURING ON BOLT FATIGUE
chapter |2 pages
axis-will cause eccentric loading and lower
bowed)-will cause eccentric loading. rough-will cause high stress concentration runout-willlead to high stress concentration.
chapter |3 pages
of the fastener manufacturer-provide a low cost product in large
of fasteners. Over the years, an enormous amount of
chapter |5 pages
of the bolt. As shown in Appendix 1, if a rigid arm is used
of a smooth round bar in tension.
chapter |3 pages
A3.B. Dimensionless Parameters
of the notched strength ratio, which is the threshold stress
chapter 2|5 pages
BOLTED JOINT AND BLOCK/INCLINE ANALOGY
la shows a block loaded by gravity on an incline. Figure lb shows the forces
chapter |1 pages
of the bolt assembly shown in Figure 6. Part C was fitted with strain
of the oscillatory torque
chapter 41|1 pages
Statistical Design and Analysis of Multivariable Experiments
EXPERIMENTATION STRATEGY
chapter |1 pages
of Statistical Designs
+1 and of Treatment Combinations in a Complete Factorial of factors (f) 5 5 10 10 of levels of each factor (L) 2 2 3 2 3 of runs (E L')
chapter 2|8 pages
6. The Eight-Run Design with All Factors at
Two Levels of eight runs and seven columns. Each row cor- 2.6.1. Using Tables 7 and 8 of factors to the columns + + + + + + + +
chapter |5 pages
of a Minimum Resolution IV Design
17-31 of 32• of factors of a complete factorial. The second group Box-Behnken designs where each factor is at
chapter |3 pages
of Multivariab/e Experiments
of the Model with Four, Eight, and 10 factors +DE) -AB - -BD -
chapter 3|2 pages
2.5. Interaction of Higher Interaction Effects
3.3.1. Basic Decomposition of squares of the different terms of the model. We again restrict ourselves to the of variance decomposition equation is of y at the ith trial [Eq. (4a)] of y at the ith trial [Eq. (6b)] of freedom.
chapter |8 pages
of Multivariable Experiments
of Variance for the Reflected Design of Beta of Mean -3.755 676.726 33.44 -0.465
chapter |1 pages
of achieving fastener initial preload always indicates
CAPABILITY of predicting fastener tension accurately. Measurement of applied of clamp load It is a fundamental rule of analysis that if more than one variable can significantly
chapter |1 pages
M-alpha SR1-UDI2239
59.9 199.9 159.9 alpha Cdeg) 199.9 59.9 : : : ·············t-····; ·········:···· ··········
chapter |1 pages
of approximately 85°, resulting in a clamping force of about
-alpha slope for the joint has been F-alpha SR1-UDI2239 ;:,;' ......................
