Fasteners, Welds, and Working Drawings Mainly: Chapters 10 (focus through Sec 19) and Chapter 11 (focus on Sec 1 through 4) Read Chapter 12 WILL NOT include drawing of fasteners such as Step by Step on pages 403, 409, 410, 417 Special thanks to Dr. Huifu Luo for his contributions to this material.

Threaded Fasteners External thread Used to hold parts together Used to adjustment parts with reference to one another Used to transmit power Standards for form, size, pitch combinations set up by: ANSI American National Standards Institute (Unified Thread Series – Inches) ISO International Standards Institute (metric) External thread Internal thread

Screw Thread Terminology see page 397 Fig. 4(b) in text, flips the naming convention for the Root and Crest of an internal thread. We will use the convention shown here.

THREAD TERMINOLOGY Major diameter Minor diameter The largest diameter on an internal or external thread. Major diameter The smallest diameter on an internal or external thread. Minor diameter External Thread Internal Thread Major dia. Major dia. Minor dia. Minor dia. Slide 4

External Thread Internal Thread COMPARISON OF MINOR and MAJOR DIAMETER REGARDING THREAD CUTTING External Thread Internal Thread Minor Dia. Major Dia. Slide 5

THREAD TERMINOLOGY Crest Root Thread angle The peak edge of a thread. The bottom of the thread cut into a cylindrical body. Root Thread angle The angle between threads faces. External Thread Internal Thread Thread angle Crest Root Root Crest Slide 6

THREAD TERMINOLOGY Right-hand thread Left-hand thread Thread that will assemble when turned clockwise. All threads considered right-handed unless specified otherwise. Right-hand thread Left-hand thread Thread that will assemble when turned counter-clockwise. Noted with an LH Turnbuckle use RH and LH thread at each end to double displacement. Slide 7

THREAD TERMINOLOGY Pitch Lead The distance from point on one thread to the same point on the next thread. For Example: between crests of threads. Pitch The distance a screw will advance when turned 360o. For a single thread L=P Lead Internal Thread External Thread Pitch Pitch Slide 8

Multiple Threads Starts Lead Indicates it is a Multiple Thread. No Start Notation (3 Starts) (2 Starts) Indicates it is a Multiple Thread. New terminology so instead of DBL for double thread it is (2 Starts) Triple thread would be indicated by (3 Starts) Starts In multiple thread Lead  Pitch Lead for (3 Starts) = 3 times the pitch Lead Multiple Threads Slide 9

THREAD CUTTING Tap Die Used to cut Internal threads Read Section 9 on page 413 Especially see the Tip on top of page 414 Used to cut Internal threads Internal threads denoted by the letter B in thread notes. Tap Used to cut External threads. External thread denoted by the letter A in thread notes Die Threading Die Tap Slide 10

THREAD TERMINOLOGY Thread Form Form is the profile shape of the thread. See Pages 398 and 399 Thread Form American National Unified Metric ACME Knuckle Buttress Most Common High Stress along one-direction of thread axis such as tubular features screwed together Loose fitting such as electric sockets and light bulbs similar to Unified Rapid traversing movement such as screw jacks and vice screws Slide 11

Thread Series See Table 1 on page 400 Detail of Shape and Number of threads per inch PITCH is a distance calculated. P=1 inch divided by the threads per inch value Numerous Series UN general stands for Unified National UNC Coarse thread for general purpose holding. UNF Fine thread used extensively in aircraft and auto construction UNEF Extra Fine thread UNR basic series but rounded the root more than the UN ones. A rounded root improves the fatigue strength. Only found on external threads. UNJ a newer specification – the root is rounded even more. Results in a larger minor diameter. Found on both external and internal threads. Constant-pitch 8UN All diameters have 8 threads per inch. Used on bolts for high pressure pipe applications. 12UN All diameters have 12 thds/in. Used in boiler work and in machine construction. 16UN All diameters have 16 thds/in. Used on adjusting collars and other applications where thread must have fine adjustment regardless of diameter.

Thread symbols FOR Thread Representations see section 2-4 PAGES 406-407 will need to recognize the 3 types OF SYMBOLS Used for Thread rEPresentatioNS but will not need to create drawings/sketches of them Detailed Thread Representation Used when diameter of thread is 1” or larger on the plotted drawing. Use when it is important to show the thread and imply its function.

Simplified & Schematic THREAD Representations Imply depth of thread with hidden lines for simplified representation Use alternating long thin & short thick lines to represent root & crest lines in schematic representation Simplified representation is called “Cosmetic Thread” in Solidworks

AutoCAD Blocks for Fasteners Found in the directory Design Center>Fasteners- US.dwg Mostly simplified representations. Slide 15

Bolts Screws Head on one end Passes through clearance holes Threaded on other end for the nut Length measured from bearing surface Threaded length is based on diameter See Appendix 17 and others Threaded Length FASTENER LENGTH Screws Greater threaded length Pass through clearance hole then other part is threaded in order to act like a nut. Many types Cap Machine Set See Appendix 18 and others, Details of lengths and other specific dimensions found there. Vary for each type. Threaded Length FASTENER LENGTH Slide 16

Thread Notes – INCH THREADS See Figure 16 on page 405 INTERNAL THREAD

Thread Notes – INCHES (continued) EXTERNAL THREAD Shown with Schematic Thread Symbol Representation

Metric Thread Notes INTERNAL EXTERNAL Drill(Minor) Diameter (mm) Drill Depth (mm) INTERNAL J 8 x 60 M J 10 x 2 Metric Symbol Thread Form Thread (Major) Diameter (mm) Thread Depth Pitch (mm) J Drill Depth Thread Depth (mm) 55 EXTERNAL Metric Tolerance Class Designation Major Diameter (mm) Pitch (mm) Reminder that metric is case-sensitive... in tolerances then lower case letters refer to shafts and upper case letters refer to holes

WELDING Representations Chapter 11 Starting on page 438 Focus sections 1-4 Most common is FILLET which has the triangle symbol See Figure 3 on page 442, Figures 4 and 5 on page 443

WELDING SYMBOL See Fig. 8 pg 444 Field Weld Symbol Weld TYPE Symbol goes here LENGTH - PITCH SIZE X XX - XXX Weld All Around means “Welder’s Choice” so it wouldn’t necessarily have all the other specifications Placement of Symbol above or below line indicates the location of weld Opposite Side Same Side

Weld Placement (continued) Symbol on BOTH SIDES Both Sides 3/8” 4” – 9” Weld Placement (continued) Weld Length Length Pitch Size Length Pitch Pitch Unequal Equal Spacing Staggered See Fig 14b pg 446

BOM stands for Bill of Materials. WORKING Drawings Read through Chapter 12 starting page 464 Working drawings provide all information needed to manufacture and assemble a product or system. Detail drawings show all necessary views, dimensions and notes needed to manufacture a part. Assembly drawings show enough information to assemble parts. A parts list identifies item number, part name, material, quantity and sometimes a company part number or other information. BOM stands for Bill of Materials. To get Bill of Materials in SolidWorks use the pull- down menu of INSERT>TABLES>Bill of Materials