S-BT Threaded Fastener Specification
Table Of Contents
- 1.1 Definition
- 1.2 The S-BT system
- 1.3 Fastening mechanism
- 1.4 S-BT system features and benefits – simplified fastening to steel
- 2.1 Grating fastening system
- 2.2 Grating fastening system X-FCS-R
- 2.3 S-BT with MM and MQ installation channel system
- 2.4 Fastening instrumentation, junction boxes and lighting
- 2.5 Fastening cable / conduit connectors
- 2.5 Fastening cable tray supports
- 2.7 Electrical connections
- 3.1 Product data
- 3.2 Load data
- 4.1 Instruction for use - S-BT-MF M6, M8, M10, W6, W10
- 4.2 Instruction for use - S-BT-MF M8/7 AN 6
- 4.3 Instruction for use - S-BT-MR M6, M8, M10, W6, W10 SN 6
- 4.4 Instruction for use - S-BT-MR M8/7 SN 6
- 4.5 Instruction for use - S-BT-MR M6, M8, M10, W6, W10 SN 6 AL
- 4.6 Instruction for use - S-BT-MR M8/7 SN 6 AL
- 4.7 Instruction for use - S-BT-GF M8/7 AN 6
- 4.8 Instruction for use - S-BT-GR M8/7 SN 6
- 4.9 Instruction for use - S-BT-GR M8/7 SN 6 AL
- 4.10 Instruction for use – S-BT-EF M6/W6/M8
- 4.11 Instruction for use – S-BT-EF M10/W10
- 4.12 Instruction for use – S-BT-ER M6/W6/M8
- 4.13 Instruction for use – S-BT-ER M10/W10
- 4.14 Instruction for use – S-BT-EF W10 HC AWG2/0 and S-BT-EF M10 HC 35/120
- 4.15 Instruction for use – S-BT-ER W10 HC AWG2/0 and S-BT-ER M10 HC 35/120
- 5.1 Nomenclature and symbols
- 5.2 Design concepts
- 5.3 Static capacity of the S-BT threaded stud
- 5.4 Vibration effects on S-BT threaded stud fastenings
- 5.5 Resistance of S-BT fastenings under dynamic tensile loading
- 5.6 Effect of S-BT threaded stud fastenings on the fatigue strength of base material structural steel
- 5.7 Influence of glue coatings on the loosening torque
- 5.8 S-BT-ER and S-BT-EF screw-in threaded studs for electrical connections
- 5.9.5 Conductivity disc of S-BT-ER / -EF electrical connectors
- 5.9.4 Stainless steel S-BT studs
- 5.9.3 Carbon steel S-BT studs
- 5.9.2 Galvanic (contact) corrosion
Specifications page89
S-BT Screw-in threaded studs
Fastener (smallarea)
Fastened part (largearea)
Carbon steel
(Duplex-coated)
S-BT-MF
S-BT-MFMT
S-BT-GF
S-BT-GFNG
S-BT-EF
Stainless steel
S-BT-MR
S-BT-MRMT
S-BT-GR
S-BT-GRNG
S-BT-ER
Electrogalvanized ◻ ◻
Hot-dipgalvanized ◻ ◻
Aluminum ◼ ◻
Structuralorcaststeel ◼ ◻
Stainlesssteel(CrNiorCrNiMo) ◼ ◻
Tin ◼ ◻
Copper ◼ ◻
Brass ◼ ◻
◻=Noimpactonlifetime
◼ =moderateimpactonlifetime,technicallyacceptedinmanycases
◼=strongimpactonlifetime
ImpactonlifetimeoftheS-BTfastenerbygalvanic(contact)corrosion
5.10.2 Galvanic(contact)corrosion
Galvaniccorrosionreferstocorrosiondamagewheretwodissimilarmetalshave
anelectricallyconductingconnectionandareincontactwithacommoncorrosive
electrolyte.
Generally,thelessnoblemetalwillbedissolved(anodicmetaldissolution),whereas
themorenoblepartisnotattackedbycorrosion(servesonlyasthecathodefor
oxygenreduction).Wheregalvaniccorrosiontakesplace,therateofcorrosionof
thelessnoblemetalishigherthanitwouldbeinafreecorrodingenvironment
withoutcontacttoanothermetal.
Galvaniccorrosioncanbeavoidedbytherightchoiceofmaterialcombinations.To
minimizegalvaniccorrosion,thedifferenceinfreecorrosionpotentialbetweenthe
materialsshouldbeaslowaspossible,and/orthesurfaceratiooflessnoblemetal
tonoblermetalshouldbeveryhigh.Thefreecorrosionpotentialdependsonthe
standardpotential,agiventhermodynamicvalueforeachmetalandthecorrosive
environment.
Asageneralruleofthumb,afastenershouldalwaysbemadeofthesameora
morenoblemetalthantheparttobefastenedinordertopreventfailureofthe
fastener.Thefastenertypicallyhasthesmallersurfacearea.
Thefollowingtableshowstheimpactofgalvaniccorrosionunderatmospheric
outdoorconditionsforvariousmaterialcombinations.
Indryindoorapplicationscontactcorrosioncanbeneglectedandusuallythereare
nosusceptiblematerialcombinations.
This is a typical case of contact
corrosion. Zinc-plated carbon steel
(washer)andstainlesssteel(screw
andpart)wereusedtogether.The
surfaceareaofthemorenoblemetal–
thestainlesssteel–islarger,causing
strongcorrosionofthewasher.
Corrosionpotentialofvariousmetalsin
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