What does "mechanical" mean here?

Question

The definition of fasteners as stated from Wikipedia is:

a hardware device that mechanically joins or affixes two or more objects together.

Is the definition of mechanical here sense 10 from Dictionary.com? I was confused because I figured the use of fasteners doesn't necessarily require machinery so if it's not the definitions related to machinery then it must mean the physical forces that you apply to the fastener when used to join things together?

Me∙ chan∙ i∙ cal [muh-kan-i-kuh l]
adjective

1. having to do with machinery: "a mechanical failure."
2. being a machine; operated by machinery: "a mechanical toy."
3. caused by or derived from machinery: "mechanical propulsion."
4. using machine parts only.
5. brought about by friction, abrasion, etc.: "a mechanical bond between stones; mechanical erosion."
6. pertaining to the design, use, understanding, etc., of tools and machinery: "the mechanical trades; mechanical ability."
7. acting or performed without spontaneity, spirit, individuality, etc.: "a mechanical performance."
8. habitual; routine; automatic: "Practice that step until it becomes mechanical."
9. belonging or pertaining to the subject matter of mechanics.
10. pertaining to, or controlled or effected by, physical forces.
11. (of a philosopher or philosophical theory) explaining phenomena as due to mechanical action or the material forces of the universe.
12. subordinating the spiritual to the material; materialistic.

Answer 1

A mechanical fastener relies on principles of mechanics to fasten materials together. This typically means that one side of the joint is prevented from moving relative to the other side of the joint by a physical abutment of the joint materials to other joint material or to the items being joined. This type of fastener includes nuts and bolts, screws, nails, velcro, etc. but excludes adhesives, glue, tape, electrostatics, magnetics, etc.

It is therefore sense 10:

pertaining to, controlled or effected by, physical forces.

Answer 2

Machinery in this sense need not be complex: a zip fastener is a simple machine, hence mechanical in sense 1. You can also fasten (some) things with a dab of superglue, which is in no sense a machine, and would not be called a fastener.

Answer 3

Senses 2 and 3, “being a machine” and “caused by or derived from machinery” are most appropriate, in that the Fasteners article refers mostly to simple machines in the forms of wedges, screws, and levers.

Answer 4

Agreed, "Sense 5" is the correct definition. "Mechanical" specifies the particular nature of the bond holding the 2 objects together -- in this case friction or abrasion as might be seen in a button, a nail, a zipper, or velcro. Alternative types of bonds might include "adhesive", "magnetic", "electro-static".

Answer 5

I don’t agree that definition 5 is the correct answer in the context of the question. It’s defining a mechanical fastening that joins two things together. In other words a fastener that is mechanically made.

From Oxford English Dictionary (OED):

mechanical, adj. and n.

Of the nature of a machine or machines; acting, worked, or produced by a machine or mechanism.

mechanically, adv.

Senses relating to machines or mechanisms.

A mechanical fastener is therefore a fastener made by machine. It therefore must be either definition 4 – using machine parts, or definition 3 – caused or derived from machinery.

Answer 6

There are mechanical fasteners, and there are fasteners. Wikipedia doesn't seem to distinguish between the two, based on the single quoted sentence in the question. Mechanical fasteners have been described at great length by other answers already (the question content provides an adequate definition of a mechanical fastener too).

The question specifically asks the following:

I figured the use of fasteners doesn't necessarily require machinery so if it's not the definitions related to machinery then it must mean the physical forces that you apply to the fastener when used to join things together?

No, that is not necessarily correct. There are fasteners such as buttons, for example. Let's put that aside, as a button doesn't actually use "fastener" in its name. A much better example is a hook-and-eye fastener. Hook-and-eye fasteners do not use adhesion, mechanical forces nor machinery to create a join. See below for an illustration.

Answer 7

Sense 5, the fastening is by friction or "etc.".