#### IfcMechanicalFastener

Natural language names

##### Semantic definitions at the entity

Entity definition

Fasteners connecting building elements mechanically.

> HISTORY New entity in IFC Release 2x2

General usage

The exact type information of the IfcMechanicalFastener is given in the ObjectType attribute inherited from IfcObject. Standard type designations are provided for guideline below.

Standard mechanical fastener type designation | Description
'Bolt' | A threaded cylindrical rod that engages with a similarly threaded hole in a nut or any other part to form a fastener.
'Nut' | A small square or hexagonal metal block with internal screw thread to be fitted onto a bolt.
'Washer' | A disk, as of metal, plastic, rubber, or other material, placed beneath a nut or at an axle bearing or a joint to relieve friction, prevent leakage, or distribute pressure.
'Screw' | A fastener with a tapered threaded shank and a slotted head.
'Nail' | A thin pointed piece of metal that is hammered into materials as a fastener.
'Rivet' | A fastening part having a head at one end and the other end being hammered flat after being passed through holes in the pieces that are fastened together.

Geometry Use Definitions:

The geometric representation of IfcMechanicalFastener is given by the IfcProductDefinitionShape, allowing multiple geometric representations. Included are:

Local Placement
The use of local placement is defined in the supertype IfcElementComponent.

Standard Geometric Representation
The use of Standard Geometric Representations is defined in the supertype IfcElementComponent.

Attribute definitions

# | Attribute | Type | Cardinality | Description | A
--- | --- | --- | --- | --- | ---
9 | NominalDiameter | - |  | This attribute is out of scope for this model view definition and shall not be set. |
10 | NominalLength | - |  | This attribute is out of scope for this model view definition and shall not be set. |

##### Inherited definitions from supertypes

Entity inheritance
Attribute inheritance

# | Attribute | Type | Cardinality | Description | A
--- | --- | --- | --- | --- | ---
IfcRoot
1 | GlobalId | IfcGloballyUniqueId | [1:1] | Assignment of a globally unique identifier within the entire software world. | X
2 | OwnerHistory | IfcOwnerHistory | [1:1] | Assignment of the information about the current ownership of that object, including owning actor, application, local identification and information captured about the recent changes of the object, NOTE: only the last modification in stored. | X
3 | Name | IfcLabel | [0:1] | Optional name for use by the participating software systems or users. For some subtypes of IfcRoot the insertion of the Name attribute may be required. This would be enforced by a where rule. | X
4 | Description | IfcText | [0:1] | Optional description, provided for exchanging informative comments. | X
IfcObjectDefinition
| IsDecomposedBy | IfcRelDecomposes @RelatingObject | S[0:?] | Reference to the decomposition relationship, that allows this object to be the composition of other objects. An object can be decomposed by several other objects. | X
| Decomposes | IfcRelDecomposes @RelatedObjects | S[0:1] | References to the decomposition relationship, that allows this object to be a part of the decomposition. An object can only be part of a single decomposition (to allow hierarchical strutures only). | X
| HasAssociations | IfcRelAssociates @RelatedObjects | S[0:?] | Reference to the relationship objects, that associates external references or other resource definitions to the object.. Examples are the association to library, documentation or classification. | X
IfcObject
5 | ObjectType | IfcLabel | [0:1] | The type denotes a particular type that indicates the object further. The use has to be established at the level of instantiable subtypes. In particular it holds the user defined type, if the enumeration of the attribute PredefinedType is set to USERDEFINED. | X
| IsDefinedBy | IfcRelDefines @RelatedObjects | S[0:?] | Set of relationships to type or property (statically or dynamically defined) information that further define the object. In case of type information, the associated IfcTypeObject contains the specific information (or type, or style), that is common to all instances of IfcObject referring to the same type. | X
IfcProduct
6 | ObjectPlacement | IfcObjectPlacement | [0:1] | Placement of the product in space, the placement can either be absolute (relative to the world coordinate system), relative (relative to the object placement of another product), or constraint (e.g. relative to grid axes). It is determined by the various subtypes of IfcObjectPlacement, which includes the axis placement information to determine the transformation for the object coordinate system. | X
7 | Representation | IfcProductRepresentation | [0:1] | Reference to the representations of the product, being either a representation (IfcProductRepresentation) or as a special case a shape representations (IfcProductDefinitionShape). The product definition shape provides for multiple geometric representations of the shape property of the object within the same object coordinate system, defined by the object placement. | X
IfcElement
8 | Tag | - |  | This attribute is out of scope for this model view definition and shall not be set. |
| ConnectedTo | IfcRelConnectsElements @RelatingElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element to which this element is connected to. |
| HasOpenings | IfcRelVoidsElement @RelatingBuildingElement | S[0:?] | Reference to the Voids Relationship that creates an opening in an element. An element can incorporate zero-to-many openings. | X
| IsConnectionRealization | IfcRelConnectsWithRealizingElements @RealizingElements | S[0:?] | Reference to the connection relationship with realizing element. The relationship then refers to the realizing element which provides the physical manifestation of the connection relationship. | X
| ConnectedFrom | IfcRelConnectsElements @RelatedElement | S[0:?] | Reference to the element connection relationship. The relationship then refers to the other element that is connected to this element. | X
| ContainedInStructure | IfcRelContainedInSpatialStructure @RelatedElements | S[0:1] | Containment relationship to the spatial structure element, to which the element is primarily associated. | X
IfcElementComponent
IfcFastener
IfcMechanicalFastener
9 | NominalDiameter | - |  | This attribute is out of scope for this model view definition and shall not be set. |
10 | NominalLength | - |  | This attribute is out of scope for this model view definition and shall not be set. |

##### Definitions applying to AISC Model View

Instance diagram

Concept usage

Properties on Occurences With Type

The Properties on Occurences With Type concept applies to this entity as shown in Table 36.

ObjectType | Property
--- | ---
Bolt | AISC_EM11_Pset_Bolt
Washer | AISC_EM11_Pset_Washer
Nut | AISC_EM11_Pset_Nut
Table 36 — IfcMechanicalFastener Properties on Occurences With Type

Exchange |
--- | ---
Import | O
Export | O

Placement

The Placement concept applies to this entity.

Exchange |
--- | ---
Import | R
Export | R

Geometric Curve Set Geometry

The Geometric Curve Set Geometry concept applies to this entity as shown in Table 37.

GeometricSet
IfcPolyline
Table 37 — IfcMechanicalFastener Geometric Curve Set Geometry

Exchange |
--- | ---
Import | O
Export | O

Polyline Path Geometry

The Polyline Path Geometry concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Mapped Geometry

The Mapped Geometry concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Element Decomposition

The Element Decomposition concept applies to this entity as shown in Table 38.

RelatedObjects
IfcMechanicalFastener
Table 38 — IfcMechanicalFastener Element Decomposition

Exchange |
--- | ---
Import | O
Export | O

Realizing Connection

The Realizing Connection concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Realizing Connection Singular

The Realizing Connection Singular concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Material Solid

The Material Solid concept applies to this entity.

Exchange |
--- | ---
Import | O
Export | O

Concept inheritance

# | Concept | Model View
--- | --- | ---
IfcFastener
| Properties on Occurrences | AISC Model View
| Simple Path Geometry | AISC Model View
IfcMechanicalFastener
| Properties on Occurences With Type | AISC Model View
| Placement | AISC Model View
| Geometric Curve Set Geometry | AISC Model View
| Polyline Path Geometry | AISC Model View
| Mapped Geometry | AISC Model View
| Element Decomposition | AISC Model View
| Realizing Connection | AISC Model View
| Realizing Connection Singular | AISC Model View
| Material Solid | AISC Model View

##### Formal representations

XSD Specification
`<xs:element name="IfcMechanicalFastener" type="ifc:IfcMechanicalFastener" substitutionGroup="ifc:IfcFastener" nillable="true"/>
<xs:complexType name="IfcMechanicalFastener">
<xs:complexContent>
<xs:extension base="ifc:IfcFastener"/>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcMechanicalFastener
SUBTYPE OF (IfcFastener);
NominalDiameter : OPTIONAL IfcStrippedOptional;
NominalLength : OPTIONAL IfcStrippedOptional;
END_ENTITY;

EXPRESS-G diagram

`

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