#### IfcFastener

Natural language names

##### Semantic definitions at the entity

Entity definition

Representations of fixing parts which are used as fasteners to connect or join elements with other elements.

> HISTORY New entity in IFC Release 2x2

General usage

The exact type information of the IfcFastener is given in the ObjectType attribute inherited from IfcObject. Standard type designations are provided for guideline below. Note that mechanical fasteners are represented by instances of the subtype IfcMechanicalFastener.

Standard fastener type designation | Description
'Glue' | A fastening connection where glue is used to join together elements.
'Weld' | A weld seam used to join together building elements.
'Jointing mortar' | Mortar used to join together building elements. The strength of the joint may be taken into consideration in calculations.

Geometry Use Definitions:

The geometric representation of IfcFastener 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.

##### 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

##### Definitions applying to AISC Model View

Instance diagram

Concept usage

Properties on Occurrences

The Properties on Occurrences concept applies to this entity as shown in Table 35.

Property
AISC_EM11_Pset_Weld
Table 35 — IfcFastener Properties on Occurrences

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

Placement

The Placement concept applies to this entity.

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

Simple Path Geometry

The Simple Path Geometry concept applies to this entity.

Welding path is a theoretical contact line between the two parts to be joined. But it does not need to be precise information and the approximation is acceptable. The Curve for welding path should be either Polyline (IfcPolyline) or Composite Curve (IfcCompositeCurve). Segments of Composit Curve should be Polyline (IfcPolyline), Line (IfcLine), or Trimmed Curve(IfcTrimmedCurve). The Basis Curve of Trimmed Curve should be either Polyine, Line, or Circle (IfcCircle).

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

Mapped Geometry

The Mapped Geometry concept applies to this entity.

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.

There are case where weld on one piece a steel plate, which is wrapped to form a circle hollow profile column (see picture below). The seam of the column is welded. This single piece welding utilizes 'Realizing Connection Singular' concept.

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
| Placement | AISC Model View
| Simple Path Geometry | AISC Model View
| Mapped Geometry | 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="IfcFastener" type="ifc:IfcFastener" substitutionGroup="ifc:IfcElementComponent" nillable="true"/>
<xs:complexType name="IfcFastener">
<xs:complexContent>
<xs:extension base="ifc:IfcElementComponent"/>
</xs:complexContent>
</xs:complexType>
`
EXPRESS Specification
`ENTITY IfcFastener
SUPERTYPE OF(IfcMechanicalFastener)
SUBTYPE OF (IfcElementComponent);
END_ENTITY;

EXPRESS-G diagram

`

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