Difference between revisions of "Metric Fasteners"

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m (Added more metrics to measure)
(New metric fasteners added)
 
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=== Cap-Head ===
 
=== Cap-Head ===
−
Cap head screws have a cylindrical head. They are most common, and useful in applications which don't require a button head geometry. They are easier to model in assemblies and have a stronger head than button-head screws.
+
Cap head screws have a cylindrical head. They are the go to fastener in most situations. They are easier to model in assemblies and have a stronger socket than button-head screws.
  
 
=== Button-Head ===
 
=== Button-Head ===
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=== Square Nut ===
 
=== Square Nut ===
−
Square nuts are similar to standard nuts, but with a square exterior. These are mostly used for inserting in 3D printed pieces, as they are stronger and easier to install compared to standard nuts.
+
Square nuts are similar to standard nuts, but with a square exterior. These are mostly used for inserting in 3D printed pieces, as they create a stronger attachment and easier to install compared to standard nuts.
  
 
=== Nylock Nut ===
 
=== Nylock Nut ===
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=== Heat-Set Inserts ===
 
=== Heat-Set Inserts ===
−
Heat set inserts are used to create stronger threads in plastic components. They are installed by heating the insert (with a soldering iron), and pressing it into a piece of plastic.  
+
Heat set inserts are used to create stronger threads in plastic components. They are installed by heating the insert (with a soldering iron), and pressing it into a hole in the plastic.  
  
 
=== Self-threading screws ===
 
=== Self-threading screws ===
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== Re-order Links ==
 
== Re-order Links ==
 
Note: If a part is out of stock or requiring shipping from a different location, the "corrosion resistance" equivalent can be substituted, however slightly more expensive.
 
Note: If a part is out of stock or requiring shipping from a different location, the "corrosion resistance" equivalent can be substituted, however slightly more expensive.
 +
{| class="wikitable"
 +
|+
 +
!Part
 +
!McMaster SKU
 +
!Link
 +
|-
 +
|M2 Socket Head, 4mm
 +
|91292A004
 +
|https://www.mcmaster.com/catalog/91292A004
 +
|-
 +
|M2 Socket Head, 6mm
 +
|91292A831
 +
|https://www.mcmaster.com/catalog/91292A831
 +
|-
 +
|M2 Socket Head, 8mm
 +
|91292A832
 +
|https://www.mcmaster.com/catalog/91292A832
 +
|-
 +
|M2 Socket head, 12mm
 +
|91292A834
 +
|https://www.mcmaster.com/catalog/91292A834
 +
|-
 +
|M2 Nut
 +
|91828A111
 +
|https://www.mcmaster.com/catalog/91828A111
 +
|}
 
{| class="wikitable"
 
{| class="wikitable"
 
|+M3
 
|+M3
Line 203: Line 229:
 
!McMaster SKU
 
!McMaster SKU
 
!Link
 
!Link
 +
|-
 +
|M3 Socket Head, 4mm
 +
|91292A109
 +
|https://www.mcmaster.com/91292A109/
 
|-
 
|-
 
|M3 Socket Head, 6mm
 
|M3 Socket Head, 6mm
Line 260: Line 290:
 
|https://www.mcmaster.com/catalog/94180A331
 
|https://www.mcmaster.com/catalog/94180A331
 
|}
 
|}
 +
{| class="wikitable"
 +
|+M4
 +
!Part
 +
!McMaster SKU
 +
!Link
 +
|-
 +
|M4 Socket Head, 6mm
 +
|91292A107
 +
|https://www.mcmaster.com/91292A107
 +
|-
 +
|M4 Socket head, 8mm
 +
|91292A108
 +
|https://www.mcmaster.com/91292A108
 +
|-
 +
|M4 Socket Head, 12mm
 +
|91292A117
 +
|https://www.mcmaster.com/91292A117
 +
|-
 +
|M4 Socket Head, 16mm
 +
|91292A118
 +
|https://www.mcmaster.com/91292A118
 +
|-
 +
|M4 Socket Head, 20mm
 +
|91292A121
 +
|https://www.mcmaster.com/91292A121
 +
|-
 +
|M4 Socket Head, 25mm
 +
|91292A122
 +
|https://www.mcmaster.com/91292A122
 +
|-
 +
|M4 Socket Head, 30mm
 +
|91292A130
 +
|https://www.mcmaster.com/91292A130
 +
|-
 +
|M4 Socket Head, 40mm
 +
|91292A132
 +
|https://www.mcmaster.com/91292A132
 +
|-
 +
|M4 Socket Head, 50mm
 +
|91292A140
 +
|https://www.mcmaster.com/91292A140
 +
|-
 +
|M4 Socket Head, 60mm
 +
|91292A048
 +
|https://www.mcmaster.com/91292A048
 +
|-
 +
|M4 Cap Head, 8mm
 +
|[[/www.mcmaster.com/94500A226|94500A226]]
 +
|https://www.mcmaster.com/94500A226
 +
|-
 +
|M4 Cap Head, 12mm
 +
|94500A228
 +
|https://www.mcmaster.com/94500A228/
 +
|-
 +
|M4 Cap Head, 16mm
 +
|[[/www.mcmaster.com/94500A282|94500A282]]
 +
|https://www.mcmaster.com/94500A282
 +
|-
 +
|M4 Thread Forming, 8mm
 +
|2815-0004-0008*
 +
|https://www.servocity.com/zinc-plated-steel-thread-forming-socket-head-screw-m4-x-8mm-length-25-pack/
 +
|-
 +
|M4 Thread Forming, 12mm
 +
|2815-0004-0012*
 +
|https://www.servocity.com/zinc-plated-steel-thread-forming-socket-head-screw-m4-x-12mm-length-25-pack/
 +
|-
 +
|M4 Thread Forming, 16mm
 +
|2815-0004-0016*
 +
|https://www.servocity.com/zinc-plated-steel-thread-forming-socket-head-screw-m4-x-16mm-length-25-pack/
 +
|-
 +
|M4 Hex Nut
 +
|91828A231
 +
|https://www.mcmaster.com/91828A231
 +
|-
 +
|M4 Nylock Nut
 +
|93625A150
 +
|https://www.mcmaster.com/93625A150
 +
|-
 +
|M4 Square Nut
 +
|96887A329
 +
|https://www.mcmaster.com/96887A329
 +
|-
 +
|M4 Washer
 +
|93475A230
 +
|https://www.mcmaster.com/93475A230
 +
|-
 +
|M4 Oversize Washer
 +
|91116A130
 +
|https://www.mcmaster.com/91116A130
 +
|-
 +
|M4 Heat-Set Inserts
 +
|94180A351
 +
|https://www.mcmaster.com/94180A351
 +
|}
 +
<nowiki>*</nowiki>Unavailable from McMaster, order from Servocity instead

Latest revision as of 04:58, 30 April 2022

ESIII has an assortment of metric fasteners useful for many projects, and free for any team to use.

Types of fasteners

M3

M3 indicates a screw is 3mm diameter, as measured by the outside of the threads. These are common in electronics and good for small prototypes.

M4

M4 indicates a screw is 4mm diameter, as measured by the outside of the threads. These are common for hardware such as medium size motors, and good for larger assemblies.

Cap-Head

Cap head screws have a cylindrical head. They are the go to fastener in most situations. They are easier to model in assemblies and have a stronger socket than button-head screws.

Button-Head

Button head screws have an arced head. They are primarily used in situations which require a small head size, such as constrained space or exterior of a rocket.

Counter-Sunk

Countersunk screws have a circular head with a chamfer into the screw. These are good for situations which the top of the head must be flush with the surface. A countersink bit can be used to create a slot for the head in the material.

Standard Nut

Standard are have a hexagonal exterior and threaded inside to hold a screw in place. They must be held in place when screwing, either with your fingers (in applications which doesn't require a tight screw), with a wrench, or with a nut driver.

Square Nut

Square nuts are similar to standard nuts, but with a square exterior. These are mostly used for inserting in 3D printed pieces, as they create a stronger attachment and easier to install compared to standard nuts.

Nylock Nut

Nylock nuts have a small rubber contact on the head of the nut. This prevents the nut from coming undone with vibrations. These nuts should be installed with the rubber portion facing away from the screw head.

Heat-Set Inserts

Heat set inserts are used to create stronger threads in plastic components. They are installed by heating the insert (with a soldering iron), and pressing it into a hole in the plastic.

Self-threading screws

Self threading screws are used to fasten materials which don't have any threads. They can simplify components by not requiring nuts or heat-set inserts. They have larger threads compared with standard screws, and as the fastener is drilled, cuts into the material to create a thread and hold the screw in place.

Dimensions

Screw Dimensions

Screw Dimensions
Measurement M3 M4
Thread diameter 3mm 4mm
Cap-Head diameter
Cap-Head length
Button-Head diameter
Button-Head length

Nut Dimensions

Nut Dimensions
Measurement Standard M3 Square M3 Nylock M3 Standard M4 Square M4 Nylock M4
Edge to Edge
Thickness
Circumscribed Diameter

Hole Dimensions

Note that with soft materials such as plastic, standard screws can also be self tapping. These can easily be stripped by over-tightening however.

Hole sizes
Measurement M3 Self-Tapping M3 M4 Self-Tapping M4
Clearance Hole 3mm (1/8 in) 3mm (1/8 in) 4mm (11/64 in) 4mm (11/64 in)
Tapping Hole 2.5mm (3/32 in) 2.2mm (3/32 in) 3.5mm (9/64 in) 3.2 (1/8 in)
Heat-Set Inserts 5mm (3/16 in) - 5.5mm (7/32 in) -

Common Fabrication Dimensions

Because 3D printers produce undersized holes, tolerances must be adjusted from the actual values. These numbers are optimized for Prusa printers.

3D printing dimensions
M3 M4
Clearance Hole 3.2mm 4.2mm
Tapping Hole (standard screw) 2.6mm 3.6mm
Tapping Hole (self-threading screw)
Hex Nut Width
Square Nut Width
Heat-Set Inserts 5mm 5.5mm
Cap-Head Clearance

Because laser cutters produce oversized holes, tolerances must be adjusted from the actual values. This can vary with material size, focus, material and laser type.

Lasercutting dimensions
M3 M4
Clearance Hole 2.8mm 3.8mm
Tapping Hole (standard screw) 2.4mm 3.4mm
Tapping Hole (self-threading screw)
Hex Nut Width
Square Nut Width
Heat-Set Inserts 4.8mm 5.3mm

Re-order Links

Note: If a part is out of stock or requiring shipping from a different location, the "corrosion resistance" equivalent can be substituted, however slightly more expensive.

Part McMaster SKU Link
M2 Socket Head, 4mm 91292A004 https://www.mcmaster.com/catalog/91292A004
M2 Socket Head, 6mm 91292A831 https://www.mcmaster.com/catalog/91292A831
M2 Socket Head, 8mm 91292A832 https://www.mcmaster.com/catalog/91292A832
M2 Socket head, 12mm 91292A834 https://www.mcmaster.com/catalog/91292A834
M2 Nut 91828A111 https://www.mcmaster.com/catalog/91828A111
M3
Part McMaster SKU Link
M3 Socket Head, 4mm 91292A109 https://www.mcmaster.com/91292A109/
M3 Socket Head, 6mm 91292A111 https://www.mcmaster.com/catalog/91292A111
M3 Socket head, 8mm 91292A112 https://www.mcmaster.com/catalog/91292A112
M3 Socket Head, 12mm 91292A114 https://www.mcmaster.com/catalog/91292A114
M3 Socket Head, 16mm 91292A115 https://www.mcmaster.com/catalog/91292A115
M3 Socket Head, 20mm 91292A123 https://www.mcmaster.com/catalog/91292A123
M3 Socket Head, 25mm 91292A020 https://www.mcmaster.com/catalog/91292A020
M3 Socket Head, 30mm 91292A022 https://www.mcmaster.com/catalog/91292A022
M3 Socket Head, 40mm 91292A024 https://www.mcmaster.com/catalog/91292A024
M3 Hex Nut 91828A211 https://www.mcmaster.com/catalog/91828A211
M3 Nylock Nut 93625A100 https://www.mcmaster.com/catalog/93625A100
M3 Square Nut 97258A101 https://www.mcmaster.com/catalog/97258A101
M3 Washer 98689A112 https://www.mcmaster.com/catalog/98689A112
M3 Oversize Washer 91116A120 https://www.mcmaster.com/catalog/91116A120
M3 Heat-Set Inserts 94180A331 https://www.mcmaster.com/catalog/94180A331
M4
Part McMaster SKU Link
M4 Socket Head, 6mm 91292A107 https://www.mcmaster.com/91292A107
M4 Socket head, 8mm 91292A108 https://www.mcmaster.com/91292A108
M4 Socket Head, 12mm 91292A117 https://www.mcmaster.com/91292A117
M4 Socket Head, 16mm 91292A118 https://www.mcmaster.com/91292A118
M4 Socket Head, 20mm 91292A121 https://www.mcmaster.com/91292A121
M4 Socket Head, 25mm 91292A122 https://www.mcmaster.com/91292A122
M4 Socket Head, 30mm 91292A130 https://www.mcmaster.com/91292A130
M4 Socket Head, 40mm 91292A132 https://www.mcmaster.com/91292A132
M4 Socket Head, 50mm 91292A140 https://www.mcmaster.com/91292A140
M4 Socket Head, 60mm 91292A048 https://www.mcmaster.com/91292A048
M4 Cap Head, 8mm 94500A226 https://www.mcmaster.com/94500A226
M4 Cap Head, 12mm 94500A228 https://www.mcmaster.com/94500A228/
M4 Cap Head, 16mm 94500A282 https://www.mcmaster.com/94500A282
M4 Thread Forming, 8mm 2815-0004-0008* https://www.servocity.com/zinc-plated-steel-thread-forming-socket-head-screw-m4-x-8mm-length-25-pack/
M4 Thread Forming, 12mm 2815-0004-0012* https://www.servocity.com/zinc-plated-steel-thread-forming-socket-head-screw-m4-x-12mm-length-25-pack/
M4 Thread Forming, 16mm 2815-0004-0016* https://www.servocity.com/zinc-plated-steel-thread-forming-socket-head-screw-m4-x-16mm-length-25-pack/
M4 Hex Nut 91828A231 https://www.mcmaster.com/91828A231
M4 Nylock Nut 93625A150 https://www.mcmaster.com/93625A150
M4 Square Nut 96887A329 https://www.mcmaster.com/96887A329
M4 Washer 93475A230 https://www.mcmaster.com/93475A230
M4 Oversize Washer 91116A130 https://www.mcmaster.com/91116A130
M4 Heat-Set Inserts 94180A351 https://www.mcmaster.com/94180A351

*Unavailable from McMaster, order from Servocity instead

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