Finding Replacement Screws for Blue Robotics Products

Introduction

Blue Robotics uses a variety of screws in its components and assemblies. Because Blue Robotics does not sell individual screws except those that are included with retail packed products, this guide may be used as a reference of where to find replacement or additional screws for your project.

General Screw Characteristics

Generally, Blue Robotics uses metric size screws, which is the international standard and easier for customers outside of the United States to obtain. When metric size screws are impractical for Blue Robotics to obtain (usually thread forming), imperial size screws are used. A metric size dimension is given afterwards for customers to locate an equivalent.

Dimensions

Metric-screws
Inch-screws

Material

316 Stainless Steel screws are corrosion resistant in wet environments, nonmagnetic, and electrically conductive.

Aluminum screws are corrosion resistant, but weaker than stainless steel. Used when galvanic corrosion may be an issue.

Nylon screws are chemical and oil resistant, non-conductive, and lightweight. May expand when exposed to moisture.

Shorthand Description

Because the thread pitch is standardized for both metric and imperial screw sizes, it is often omitted. Screw descriptions are often written in shorthand as the following example:

  • M3x12 = Screw thread diameter by thread length (mm)
  • #4×0.5″ = Numbered screw diameter by thread length (inch)

Locating Where Screws are Used in Blue Robotics Retail Packaging (RP)

Screws used in all Blue Robotics products can be found in two locations:

    1. The “Contents” section of a product page.

    2. The assembly guide steps for the relevant product.

Contents Section of a Product Page

The “Contents” section of each product page lists the loose screws that come with each product in its retail packaging. Screws already installed on a product assembly are not included with this list.

screw-guide-contents-box

Assembly Guides

Screws used during the assembly or integration guides are called out during each step.

screw-guide-guides-box

Locating Where Screws are Used in Blue Robotics Assembled Products (ASM)

For screws on pre-assembled products, the type and dimensions may be determined by following these steps:

    1. Remove the screw from the assembly. Remember where it came from for reassembly. Taking pictures along the way may help.

    2. Measure the thread diameter using a set of calipers.

    3. Measure the thread length from the base of the head to the end of the end of the screw, unless otherwise specified from the screw characteristics.

Screw Sourcing

McMaster-Carr: McMaster-Carr is Blue Robotics’ preferred hardware store when prototyping. The company has one of the most complete collections of fasteners and other items for rapid project work.

Amazon: For smaller numbers of screws it may be more beneficial to find what you need on Amazon.

Screws Used in Blue Robotics Products

Socket Head Cap Screws

These standard socket head screws have a head height that matches the screw’s thread diameter.

Socket Head Cap Screw Example
Head TypeThread DiameterThread LengthThread PitchMaterialDriver TypeDriver SizeMcMaster-Carr Part# (USA)
SocketM28 mm0.4 mmSS316Hex1.5 mm92290A015
SocketM210 mm0.4 mmSS316Hex1.5 mm92290A017
SocketM35 mm0.5 mmNylonHex2 mm93640A124
SocketM35mm0.5 mmAluminumHex2 mmCustom Item, ask Blue Robotics if needed
SocketM312 mm0.5 mmSS316Hex2 mm92290A115
SocketM316 mm0.5 mmSS316Hex2 mm92290A120
SocketM320 mm0.5 mmSS316Hex2 mm92290A122
SocketM414 mm0.7 mmSS316Hex3 mm92290A150
SocketM416 mm0.7 mmSS316Hex3 mm92290A154
SocketM418 mm0.7 mmSS316Hex3 mm92290A161
SocketM420 mm0.7 mmSS316Hex3 mm92290A168

Low Profile Socket Head Cap Screws

With half the head height of a standard socket head, they fit where space is limited, but their low profile makes their head weaker.

Low Profile Socket Head Cap Screw Example
Head TypeThread DiameterThread LengthThread PitchMaterialDriver TypeDriver SizeMcMaster-Carr Part# (USA)
Low Profile SocketM34 mm0.5 mmSS316Hex2 mm92855A301

Button Head Cap Screws

These screws have rounded heads and are suitable for use on exterior surfaces to reduce snags.

Button Head Cap Screw Example
Head TypeThread DiameterThread LengthThread PitchMaterialDriver TypeDriver SizeMcMaster-Carr Part# (USA)
ButtonM2.512 mm0.45 mmSS316Hex1.5 mmCustom Item, ask Blue Robotics if needed
ButtonM35 mm0.5 mmSS316Hex2 mm94500A263
ButtonM36 mm0.5 mmSS316Hex2 mm94500A221
ButtonM38 mm0.5 mmSS316Hex2mm94500A222
ButtonM325 mm0.5 mmSS316Hex2 mmCustom Item, ask Blue Robotics if needed
ButtonM48 mm0.7 mmSS316Hex2.5 mm94500A226
ButtonM410 mm0.7 mmSS316Hex2.5 mm94500A227
ButtonM512 mm0.8 mmSS316Hex3 mm94500A231
ButtonM516 mm0.8 mmSS316Hex3 mm94500a232

Set Screws

Cup point set screws have a thin edge that digs into the contact surface for a secure hold on a wide range of surfaces.

Set Screw Example
Head TypeThread DiameterThread LengthThread PitchMaterialDriver TypeDriver SizeMcMaster-Carr Part# (USA)
Cup Point SetM33 mm0.5 mmSS316Hex1.5 mm92029A100
Cup Point SetM35 mm0.5 mmSS316Hex1.5 mm92029A102
Cup Point SetM44 mm0.7 mmSS316Hex2 mm92029A140

Flat Head Screws

These screws are angled under the head to sit flush within countersunk holes. Length is measured from the top of the head.

Flat Head Screw Example
Head TypeThread DiameterThread LengthThread PitchMaterialDriver TypeDriver SizeMcMaster-Carr Part# (USA)
Flat Head (Phillips)M310 mm0.5 mmSS316Phillips#191801A156
Flat Head (Phillips)M312 mm0.5 mmSS316Phillips#190198A105

Thread Forming Screws

These screws have a rounded head, excellent resistance to chemicals and salt water and may be mildly magnetic. They press tightly against formable plastic to resist loosening.

Thread Forming Screw Example
Head TypeThread DiameterThread LengthThread PitchMaterialDriver TypeDriver SizeMcMaster-Carr Part# (USA)
RoundedM24 mm0.4 mmSteelTorx PlusIP6, T694209A312
Rounded#40.5 in20/inchSS316Phillips#199461A286
Rounded#40.625 in24/inchSS316Phillips#190184A110
Rounded#40.75 in24/inchSS316Phillips#190184A111
Rounded8-180.25 in18/inchSS316Phillips#292525A805
Rounded8-180.5 in18/inchSS316Phillips#292525A818
Rounded8-180.625 in18/inchSS316Phillips#292525A820