OnShape: Nut and Bolt Tutorial

By: Matthew Jourden

Brighton High School

Brighton, MI

Objective: Design a Commercially Off Shelf (COTs) Nut and Bolt with a detailed thread. COTs Parts are considered to be

standardized parts. Parts like nuts, bolts, screws, washers, cotter pins, woodruff keys, etc. are standardized based on one

measurement. An engineering can gather the necessary resources from a variety of manuals like Machinery Handbook, ANSI or

ISO manuals or Appendix on a Engineering Textbook (see below). The various measurements of fasteners will typically be a

factor of the Major Diameter of the Thread. Utilizing reference charts (see below) will save the engineer time in having to

calculate out the various measurements of a fastener.

Thread Representation

Parts to a Thread

Thread Dimension

Charts: Nut and Bolt Sizes

Major Diameter

1. Navigate to brightonk12.onshape.com > Create a New Document > Rename Tutorial Nut and Bolt

2. Bolt Creation: ½-13UNC-2B

a. Rename Part Studio 1 > Bolt: Detailed

b. Bolt Body

i. Select Sketch > Rename Sketch to Bolt Body > Select Top Workplane (Datum) > Draw the following circle

> Green Check > Select Extrude Icon > Rename Bolt Length > Extrude Length 2 > Green Check to Accept

c. Chamfer: Chamfers are used at the end of a fastener or top of a bolt ahead to make it easier for alignment into

the mating feature (i.e. the bolt shaft into the threaded hole or align the sockets wrench)

i. Select Chamfer Tool > Select the edge of the lower circle (bottom edge of part) > Set Value at

.0625 > Green Check to Accept

d. Bolt Hexagonal Head

To create the bolt head designer will need to first draw a construction circle that will represent the distance

between the corners of a hexagon the then circumscribe a hexagon on the inside of the circle. Using Constraints

the user will then make the hexagon equal length. In the end the designer needs to only set 1 dimension (Circle

Measured Across the Corners).

i. Select Sketch > Rename Sketch to Bolt Head > Select the Top Flat edge of the Bolt Length Extrude

ii. Draw the following Construction Circle (NOTE: Dimension based on Variable G Width Across the

Corners) and Construction Lines

NOTE: There is a Max and Min; this is because the mating feature (socket wrench) has a variance the

size of the bolt head and socket opening can be and the two will still mate. In the end it does not matter

which value we choose as long as it is between these two values.

In this tutorial we will use Dimension Diameter = .866

Construction Lines will be used to help scribe the hexagon and later create the chamfer on top of the

bolt head.

Select Top

Surface

iii. Draw the Following Hexagon. Be sure

1. to make two of the points meet at the intersection of the construction circle and construction

lines.

2. Top and Bottom edge are horizontal

3. All Points touch the Construction Circle

iv. Select Equal Length Constraint Icon > Select Edges to make them Equal Length.

NOTE: Designer should only have to make 3 of 6 lines equal length to make all 6 equal length due to the

design of the hexagon being anchored to the construction circle

NOTE: Hexagonal lines should turn black when lines are fully constrained

v. Green Check to Accept Sketch

vi. Select Extrude Icon > Rename Extrude to Bolt Head > Set Extrude Distance to Variable H (11/32) based

on the Chart above

vii. Green Check to Accept Extrude

viii. Bolt Head Chamfer

In this scenario the chamfer icon cannot be used because the chamfer will not be formed correctly. We will

need to revolve cut the chamfer in order to cut all edges correctly.

1. Select Sketch Icon > Rename Sketch to Bolt Head Chamfer > Select the Workplane that passes

through the two corners of our bolt head that were sketched intersecting the Construction

Circle and the Construction Lines (For tutorial demo that would be the Front workplane (Turn on

the workplanes to see which plane passes through the corners). This is important to have these

two points pass through a workplane in order to get the chamfer to form correctly.

2. Draw the following profile and construction line > Green Check to Accept Sketch

Plane Passes

through the corners

of hexagon

Construction Line

located at the center of

the bolt

3. Select Revolve Icon > Rename Extrude to Bolt Head Chamfer > Select Remove Tab >

Profile/Faces: Select Bolt Head Chamfer Sketch > Axis Line: Select Construction Line > Select

Merge with All > Green Check to Accept

e. Detailed Threads

i. Select Helix Icon (Either located on the Tool Bar or in the drop down menu below the Plane Icon)

> Rename Helix to Detailed Thread > Switch Setup from Turns to Height and Pitch > Select the Top Circle

of the Chamfer (.50) > Set Height at 1.5 > Set Helical Pitch little larger than the actual pitch (pitch is the

distance between peaks on the thread) a of the thread (Actual Pitch 1/13 (13 threads per inch) set to

.085 > Green Check to Accpet

Axis Line

Change to Height and Pitch

Select Top Edge of Chamfer. This

will make it so the helix wraps

around the outside edge of the

cylinder (Major Diameter)

ii. Select Sketch Tool > Rename Sketch to Thread Profile > Select the Workplane that was used to create

the chamfer on the bolt head (should be Front or Right; for this tutorial the right plane was selected) >

Draw the following profile > Green Check to Accept

NOTE: The triangle is

1. Set outside of the part and material side (For this tutorial Quadrant 4 of a grid)

2. Equilateral

3. 1 Dimension is set to the actual Pitch of the thread 1/13 (13 threads per inch)

NOTE: May use the Use, Construction Tool to help located the triangle

Use Tool and Construction Tool to find

edges not on the same plane as sketch >

Line Tool and Construction tool to find

corner point of part

iii. Select Sweep Tool > Rename Sweep to Detailed Threads > Select Remove Tab > Faces/Sketch:

Select Triangle Sketch or Thread Profile from Model Tree > Sweep Path: Select Helix Line on the Solid

Model > Check Merge with All

Select Helix on the

part NOT from the

Model Tree

NOTE: The Detailed Thread Helix is still visible. To

Hide Select Eyeball next to Curves from the Model

Tree (Located at the bottom of the model Tree) this

will hide the Helix Sketch

3. Nut Creation: ½-13UNC-2B

a. Create new Part Studio Tab in the Tutorial Nut and Bolt Document > Rename Tab Nut Creation

b. Nut Body

i. Select Sketch Tool > Rename Sketch Nut Profile > Select Top Workplane > Draw a Construction Circle

equal to Variable G Width Across the Corners (.866) and Construction Lines that provide 2 of the 6

corner points to help with revolving the chamfer

ii. Scribe a Hexagon on the interior of the circle with

1. to make two of the points meet at the intersection of the construction circle and construction

lines.

2. Top and Bottom edge are horizontal

3. All Points touch the Construction Circle

4. All lines are equal (Use the Equal Constraint to set lines equal to each other)

And

Draw a circle in the center that represents the major diameter of the threaded hole

5. Green Check to Accept Sketch

iii. Select Extrude Tool > Rename Extrude to Nut Body > Extrude Distance from the Chart use Variable H

Thickness of Hex Nuts: 7/16 > Select from the work area the area between the hexagon and the inner

hole; this will create a hole in the center of the hex nut > Green Check to Accept

iv. Hex Chamfer

1. Select Sketch Icon > Rename Sketch Hex Chamfer > Select Workplane that pass through the two

points of the hexagon > Sketch the following sketch > Green Check to Accept

2. Select Revolve Tool > Rename Revolve to Hex Chamfer > Select Remove Tab > Faces/Sketch:

Select Triangle > Axis Line: Select Construction Line > Check Merge with All > Green Check to

Accept

Select Area between hexagon

and inner circle

c. Thread Body

i. Turn on Sketch Nut Profile by placing cursor on the model tree name > Select the Eyeball next to the

name unhide

ii. Select Extrude Tool > Rename Thread Surface > Select New Tab > Select Circle Edge of the Hole from the

bottom (opposite of the chamfer end) > Extrude Distance (Distance needs to be a minimum 1 thread

length longer than the nut in order to have the threads exit the hole in the thread correctly) Set at 1” >

Green Check to Accept > Hide Sketch Nut Profile by clicking on the eyeball next to the sketch in the

model tree

NOTE: There should be two parts listed in the model Tree. Change the Names to the following

iii. Hide Hex Nut (Part 1) from the model tree

iv. Select Helix Tool > Rename Helix to Thread Helix > Change type to Pitch (this will create the helix along

the entire cylinder) > Select Cylindrical Face of Thread Surface (Part 2) > Pitch .085 (Same as bolt; so

when assembled user can match the threads up) > Green Check to Accept

v. UnHide Part Hex Nut (Part 1) and Change View Display to Hidden Edges Visible

vi. Select Sketch Tool > Rename Sketch to Thread Profile > Select same workplane as the Revolved Chamfer

that goes through 2 of 6 points > Draw the Following (To gain references use the Use Tool) > Green

Check to Accept Sketch

vii. NOTE: The triangle is

1. Set Inside of the part and material side of Thread Surface (Part 2) (For this tutorial Quadrant 4 of

a grid)

2. Equilateral

3. 1 Dimension is set to the actual Pitch of the thread 1/13 (13 threads per inch)

Use Tool and Construction

Tool > Select Circle to Show

Location of edge of circle

Pitch of Thread

viii. Select Sweep Tool > Rename Sketch to Thread Body > Select Add Tab > Face/Sketch: Select Triangle >

Path: Select Helix from the Workspace > Body Scope: Select Hex Nut (Part 1) from the Model Tree >

Green Check to Accept

NOTE: DO NOT select Merge with All

ix. Hide Curves from the Model Tree.

NOTE: Cleanup Work will still need to be cleaned up

Select Merge Scope = Hex Nut (Part 1)

NOTE: Extrude Cut to

show interior details

x. Select Thread Surface > Press Delete Key on the Keyboard or Right Click on Thread Surface Name and

Select Delete > Green Check the Delete Feature > On the Model Tree Delete Thread Surface will appear

xi. Select Sketch Tool > Rename Sketch to Thread Cleanup > Select Front or Right Workplane > Draw two

rectangles from the edge of the hex nut extending to include all of the excess thread material > Select

Green Check to Accept

NOTE: Use Tool and Construction Tool to find location off the edge of the hex nut

xii. Select Extrude Tool > Rename Extrude to Thread Cleanup > Select Remove Tab > Select Thread Cleanup

Sketch from Model Tree > Change Extrude type to Symmetric > Extrude Distance set to 1.5 (larger than

the diameter of the hole to cut away all material)

4. Assembly Nut and Bolt

Goal: Match up Threads

a. Select Assembly Tab

b. Insert Bolt > Fix in Default Location

c. Insert Nut > Place away from the Bolt > Select Fastened Constraint > Select center points from both objects

NOTE: Chamfer from the nut should be facing the end of the threads on the bolt (Flip constraint direction as

needed.

d. Set Offset Distance Z to the height of the nut 7/16 (this will make the chamfer end of the nut flush with the end

of the bolt (NOTE: technically the nut could be anywhere along the thread; we are just trying to match up the

threads.)

NOTE: Notice how the threads do not match up. This is do to how the helix start point is created in OnShape.

To Correct this we will create a layout with a full section and find the difference between the two threads and

adjust the Z Offset

e. Create a Drawing Tab > Place Hexagonal View of the Assembly (Top View) > Create a Full Section Thru the Center

of the Hex Head creating an assembly section view

f. Measure Between Threads > Modify Z Offset on the Assembly by this Value > Update Drawing to check if

threads match up (If not check with a new dimension and repeat steps)

Distance between Bolt Thread and Nut

Thread

Adjust Fastened Constraint on Assembly with Measured Value

Update Drawing to see if Threads Matchup

Submission: Show Teacher upon Completion