What Are SEMS?
SEMS are a Screw / Bolt combination with a permanently attached washer or set of washers. It is also called as washer assembled screw, captivated washers, Screw washer assemblies, bolt washer assemblies, combi screws or combi bolts. The word SEMS originates from The Illinois Tool Works Inc., who made machines that produced pre-assembled screw and washers. In spite of the original patents and trademarks, the word SEMS is generally recognised as a generic term applicable to screw and washer assemblies. The washers are assembled on the bolt or screw blanks before threads are rolled. Since the outer diameter of the threads are higher than the inner diameter of the washers, which does not allow washers to come out.
Washer assembled sems screw or captive screw offers several benefits in terms of faster or easier assembly and handling. Ensures faster product assembly, thanks to pre-assembled and pre-lubricated parts.
We offer following sems screws off the shelf:
| Head Style : | » Slotted Pan Head
» Hex Philips Head » Hex Head » Hex washer head |
» Cheese Head » Pan Philips Head / Pan Combi Head etc » Allen Socket Head » Torx Head |
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| Washer Types : | » Internal
» Plain Washer » Spring Washer » Internal Tooth Washer |
» External Tooth Washer |
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Plain Washers for Screw and Washer Assemblies (Sems Screw) reference standards
- Din 6902 A : Plain Washer for Screw and Washer Assemblies – Type A
- Din 6902 B : Plain Washer for Screw and Washer Assemblies – Type B
- Din 6902 C : Plain Washer for Screw and Washer Assemblies – Type C
- Din 6903 A : Plain Washer for tapping Screw and Washer Assemblies – Type A
- Din 6903 B : Plain Washer for tapping Screw and Washer Assemblies – Type B
- Din 6903 C : Plain Washer for tapping Screw and Washer Assemblies – Type C
- DIN EN ISO 10673 (S) : Plain Washer for Screw and Washer Assemblies – Type S
- DIN EN ISO 10673 (N) : Plain Washer for Screw and Washer Assemblies – Type N
- DIN EN ISO 10673 (L) : Plain Washer for Screw and Washer Assemblies – Type L
- DIN EN ISO 10669 (S) : Plain Washer for tapping Screw and Washer Assemblies – Type S
- DIN EN ISO 10669 (N) : Plain Washer for tapping Screw and Washer Assemblies – Type N
- EN ISO 10669 (L) : Plain Washer for tapping Screw and Washer Assemblies – Type L
- JIS B 1258 (S) : Plain Washer for Screw and Washer Assemblies – Type S
- JIS B 1258 (N) : Plain Washer for Screw and Washer Assemblies – Type N
- JIS B 1258 (L) : Plain Washer for Screw and Washer Assemblies – Type L
- DIN 6907 : Serrated Lock Washers With External Teeth For Screw And Washer Assemblies
- DIN 6905 : Spring Lock Washers for Screw and Washer Assemblies
Note : Any types of SEMS Screw can be developed as per customer’s requirement & specifications.
