Khoom Description
Peb lub tuam txhab tsom mus rau kev tshawb fawb, kev tsim kho, thiab tsim khoom ntawm Riveting Contact Assembly, npog plaub series:Copper Hauv -Tuag Riveting; Brass In-Tuag Riveting; Beryllium Copper Hauv -Tuag Riveting; thiab Stainless Hlau Hauv -Tuag Riveting.Cov Riveting Contact Assembly ua tau raws li qhov xav tau ntawm ntau qhov chaw, xws li lub zog, lub zog tshiab, thiab cov khoom siv hauv kev lag luam.
Product Classification thiab Cov yam ntxwv
1. Copper Hauv -Tuag Riveting
Raws li cov tub ntxhais conductive Copper Contact Rivetings ntawm qis- cov khoom siv hluav taws xob hluav taws xob, qhov ua tau zoo ntawm tooj liab stamping qhov chaw ncaj qha cuam tshuam rau cov khoom siv hluav taws xob 'kev ntseeg siab thiab kev pabcuam lub neej. Cov tooj liab stamping qhov chaw peb tsim muaj cov yam ntxwv tseem ceeb hauv qab no:
1.1 Nyob rau hauv cov nqe lus ntawm Materials Science
Peb xaiv siab -purity tooj liab strips xws li C1100 thiab T2Y2, nrog cov ntsiab lus tooj liab ntawm Ntau dua lossis sib npaug li 99.99%, kom ntseeg tau zoo heev conductivity (conductivity Ntau dua lossis sib npaug rau 98% IACS) thiab thermal conductivity. Tsim ib tug series ntawm cov ntaub ntawv daws teeb meem rau txawv daim ntawv thov scenarios:
| Cov cai thov | Khoom qauv | Cov ntsiab lus tooj liab | Hluav taws xob conductivity (%IACS) | Tensile zog (MPa) |
| High conductive qhov chaw | tooj liab tshwj xeeb | Ntau dua lossis sib npaug li 99.99% | 100 | - |
| Siab -lub zog qhov chaw | C1100/T2Y2 | Ntau dua lossis sib npaug li 99.99% | Ntau dua lossis sib npaug li 98 | 300-400 |
1.2 Hais txog Precision Forming Technology
Txoj kev vam meej tuag stamping txheej txheem rau Copper Stamping Nrog Riveted Silver Contacts ua tiav qhov tseeb qhov tseeb ntawm ± 0.01mm. Los ntawm kev tsim ntawm ntau- chaw nres tsheb loj zuj zus tuag, ntau txoj hauv kev xws li xuas nrig ntaus, khoov, thiab ua tiav tuaj yeem ua tiav hauv ib qho kev sib tsoo, nrog rau kev ua haujlwm ntawm 200 - 300 zaug ib feeb. Lub hauv paus "micro-deformation" stamping technology nta:
Optimizing blanking clearance (tswj ntawm 5 - 8% ntawm cov khoom thickness)
Txais yuav ob -sab shearing txheej txheem
Ua kom qhov kev faib ua feem ntawm thaj chaw ci ntsa iab ntawm qhov chaw txiav mus rau ntau dua 85% txo qis kev ua haujlwm tom ntej
1.3 Nyob rau hauv cov nqe lus ntawm cov txheej txheem kho deg
| Hom txheej txheem | Technical nta | nyhuv |
| Inert gas tiv thaiv | Anti-kev kho oxidation | Surface stability txhim kho |
| Tin / silver plating | Daim ntawv thov tshwj xeeb scene | Contact resistance reduction>30% |
1.4 Kev tshuaj xyuas hauv -Pwm Riveting txheej txheem rau cov neeg mob nyiaj
Kev txhim khu kev qha kev sib txuas ntawm cov nyiaj sib cuag thiab tooj liab substrate yog qhov tseem ceeb rau kev ua haujlwm ntev - lub sij hawm ruaj khov ntawm cov khoom siv hluav taws xob. Peb cov thev naus laus zis tau ua tiav cov txheej txheem kev hloov pauv hloov pauv:
(1) Raws li kev tsim qauv tsim
| Tsis muaj | Performance indicators, As |
| Kev sib cuag cheeb tsam nce | 40% |
| Tiv tauj tiv thaiv | Tsawg dua lossis sib npaug li 50μΩ |
| Mechanical life test | 100,000 zaug (tsis kam hloov Tsawg dua lossis sib npaug li 10%) |
(2) Raws li Kev Tswj Xyuas Txheej Txheem
Cov txheej txheem hauv -pwm riveting rau cov nyiaj sib cuag nyob rau hauv kev vam meej tuag stamping paub tag nrho - txheej txheem kev soj ntsuam:
Lub multi-axis quab yuam tswj system tswj lub riveting siab raug nyob rau hauv ± 1.5%.
Ua kom muaj qhov sib xws ntawm qhov zoo ntawm txhua qhov riveting point.
1.5 Kev nce qib ntawm cov txheej txheem technical
Peb cov txheej txheem ntau lawm ua kom pom cov qib kev tshaj lij hauv ntau qhov ntev:
(1) Hais txog Die Technology
Kev siv cov cemented carbide zuj zus tuag nrog kev pab cuam lub neej ntau dua 30 lab lub sijhawm.
CAD/CAE kev tsim qauv ua kom muaj kev sib raug zoo ntawm hauv - pwm riveting chaw nres tsheb, nrog cov coaxiality tswj hauv φ0.015mm.
Tus thawj elastic stripper system daws qhov teeb meem deformation ntawm nyias Nyiaj Hluav Taws Xob Riveted Cheebtsam, ua tiav qhov flatness ntawm 0.05mm / 100mm.
(2) Nyob rau hauv cov nqe lus ntawm txheej txheem tswj Technology
Cov kab ntau lawm yog nruab nrog lub tshuab hluav taws xob tsis pom kev hauv online, ua 100% kev tshuaj xyuas tag nrho ntawm qhov loj me, thiab cov ntaub ntawv raug xa mus rau MES system hauv lub sijhawm tiag tiag rau kev taug qab zoo.
Qhov kev hloov kho ntse ntse tau ua kom zoo dua qhov ntsuas qhov ntsuas raws li cov yam ntxwv ntawm cov khoom siv, ua kom cov txheej txheem ruaj khov.
(3) Nyob rau hauv cov nqe lus ntawm kev txuag hluav taws xob thiab Environmental Protection Technology
Kev siv cov khoom siv tooj liab tam sim no ua tiav cov khoom siv ntau dua 85%.
Cyanide- txheej txheem nyiaj dawb plating thiab cov dej khib nyiab kaw- txoj hlua kho tau ua raws li RoHS thiab REACH cov qauv kev tiv thaiv ib puag ncig, lav kev nkag mus rau siab - kawg European thiab Asmeskas kev lag luam.
1.6 Daim ntawv thov thaj chaw thiab kev ruaj ntseg zoo
Daim ntawv thov ntau yam: relays, keyboards, contactors, circuit breakers, thermostats, thiab lwm yam.
Daim ntawv pov thawj system:IATF16949, ISO9001.
Cov khoom kuaj kuaj:
Conductivity (kev tiv thaiv, kub nce)
Mechanical zog (lub zog tensile, bonding force)
Durability (mechanical / hluav taws xob lub neej)
Ib puag ncig kev ntseeg siab (ntsev tshuaj tsuag, damp kub)
2. Brass In-Tuag Riveting
Brass (xws li H65, thiab H70) tau dhau los ua cov khoom siv zoo tshaj plaws rau kev sib txuas lus vim nws cov khoom siv hluav taws xob zoo heev, txhua yam muaj zog, thiab corrosion kuj. Qhov tseem ceeb ntawm kev zoo ntawm peb cov tooj dag stamping qhov chaw yog raws li hauv qab no:
2.1 Material Science Optimization
| Yuav tsum thov | Hom khoom | Key Performance Parameters |
| General conductive scenarios | High - cov khoom siv tooj dag (CuZn30, CuZn37) | Hluav taws xob conductivity Ntau dua lossis sib npaug li 28% IACS, elongation Ntau dua lossis sib npaug li 15% (zoo ductility) |
| Differentiated mechanical zog xav tau | Mos/semi-tooj / tawv tawv | Tensile zog xws li ntawm 250 - 600 MPa (annealed/unannealed) |
2.2 Precision Stamping Forming Technology
Cov txheej txheem Efficiency: Progressive tuag stamping ua tiav ntau yam txheej txheem xws li xuas nrig ntaus, khoov, thiab ncab hauv ib leeg tuag stroke, nrog kev ua haujlwm ntawm 200 - 400 zaug hauv ib feeb.
Precision Control:
| Cov ntsiab lus tseem ceeb | Performance Indicators |
| Micro{0}}Gap blanking tshuab | Qhov sib txawv=5% - 8% ntawm cov khoom thickness, ci cheeb tsam loj dua los yog sib npaug rau 80% |
| Kev pab lub neej ntawm siab -precision progressive tuag | Ntau dua lossis sib npaug li 30 lab lub sijhawm, qhov ntev ntev ± 0.02 hli |
Tus nqi tseem ceeb: Txo cov burrs, txhim kho kev sib cuag hluav taws xob, thiab ua tau raws li qhov yuav tsum tau ua ntawm siab -kawg keyboards.
2.3. Kev kho deg thiab tiv thaiv -corrosion
| Kev kho mob | Core Zoo | Performance Parameters |
| Nickel plating / tin plating / passivation | Txhim khu kev tiv thaiv -oxidation muaj peev xwm | Tshuaj tsuag ntsev rau 48 - 96 teev |
| Xaiv nyiaj plating | Txo kev tiv thaiv kev tiv thaiv, txhim kho hluav taws xob lub neej | Tiv tauj tsis kam Tsawg dua lossis sib npaug li 50 μΩ |
2.4 Kev sib txuam muaj peev xwm ntawm Brass Stamping, Silver Contact Riveting, thiab Screw Assembly
Peb muab ib qho - nres modular Hluav Taws Xob Sib Txuas Sib Txuas Cov Kev Pabcuam Brass Stamped Part ntawm "stamping - riveting - sib dhos":
(1) Precision Integration Technology
| Cov txheej txheem tseem ceeb | Technical Parameters | Cov txiaj ntsig zoo |
| Tus kheej -tapping ntsia hlau qhov stamping | Installation txoj hauj lwm raug ± 0.03 hli, zam tapping deformation | - |
| Kev vibration lub tais noj, tsis siv neeg riveting, thiab screwing | Kev sib dhos ua haujlwm ntawm 30, 000 - 40,000 PCS / H (10 npaug sai dua li kev ua haujlwm ntawm phau ntawv) | Txo cov kev cuam tshuam ntawm phau ntawv, txhim kho qhov sib xws |
(2) Screw Fastener Optimization
Specification Range: M2 - M10 stainless hlau / tooj liab ntsia hlau
Kev ntseeg tau tsim:
torque tswj qhov tseeb ± 5% (tiv thaiv kev xoob thiab stripping)
Kev xaiv threadlocker lossis xauv lub tshuab ntxhua khaub ncaws (ruaj khov hauv qhov chaw vibrating)
(3) Automated Detection System
100% Kev Tswj Xyuas Zoo:
CCD qhov muag pom kev pom: Pom cov ntsia hlau ntsia hlau txoj haujlwm
Torque sensor + micro-ohmmeter: Ib txhij kuaj xyuas cov khoom siv hluav taws xob thiab hluav taws xob conductivity
3. Beryllium Copper Hauv -Tuag Riveting
Beryllium tooj liab (BeCu), muaj lub zog siab, siab elasticity, qaug zog tiv thaiv, thiab corrosion kuj, yog cov khoom siv zoo tagnrho rau cov khoom tseem ceeb xws li relay txav reeds thiab microswitch caij nplooj ntoos hlav daim. Lub ntsiab kev zoo ntawm peb cov beryllium tooj liab stamping qhov chaw yog raws li nram no:
3.1 Cov yam ntxwv ntawm Beryllium Copper Stampings
(1) Material Science Optimization
| Daim ntawv thov Scenario | Khoom Qib | Key Performance Parameters |
| Relay txav reeds | C17200 (siab elasticity) | Cov ntsiab lus 1.8% -2.0%, tensile zog 1200-1400 MPa, HV 380-420 |
| Automotive relay armatures | C17500 (siab zog) | Hluav taws xob conductivity 18–22% IACS, HV 400–450 (hnav-resistant) |
| Cov txheej txheem hauv paus | Kev daws + hnub nyoog kev kho cua sov | Sib npaug siab elasticity (deformation rov zoo dua los yog sib npaug li 98%) thiab conductivity |
(2) Precision Stamping Technology
Dimensional Accuracy: Progressive tuag stamping tiav ± 0.01 hli precision, haum rau 0.05-0.3 hli ultra- nyias BeCu strips los tiv thaiv kev tawg / deformation
Tuag Technology:
| Tuag Hom | Core Metrics |
| Cemented carbide progressive tuag | Kev pabcuam lub neej Ntau dua lossis sib npaug rau 5 lab lub voj voog, ruaj khov ntau lawm |
| Blanking clearance optimization | 4-6% ntawm cov khoom thickness, burrs Tsawg dua los yog sib npaug rau 0.01 hli |
Nto Zoo:Smooth txiav nto txo cov ncej- ua, ntsib ncaj qha Beryllium Copper Punch Hu rau Riveted Terminals yuav tsum tau
3.2 Automotive-Qib Siab-Efficiency Assembly Technology
Rau kev sib dhos meej ntawm BeCu txav reeds + nyiaj tiv tauj + armature stampings hauv tsheb relays thiab siab -kawg keyboards, peb ua tiav kev tsim khoom:
(1) Peb-hauv-Ib Hauv-Pwm Riveting txheej txheem
Fully Integrated nyob rau hauv ib leeg Progressive tuag:
1. BeCu txav reed stamping (siab -elasticity qauv tsim)
2. Tsis siv neeg nyiaj kev sib cuag riveting (tsawg-kev twb kev txuas)
3. Precision sib dhos ntawm armature stampings (txhim kho qhov chaw)
Efficiency Gains:Shortens ntau lawm voj voog los ntawm 50% thiab txo cov nqi zog los ntawm 60% piv rau cov tsoos multi- kauj ruam sib dhos
(2) Precision Positioning & Automation
| Ntsiab Technology | Precision Metrics | Kev Ua Tau Zoo |
| CCD qhov muag pom qhov system | Alignment raug Tsawg dua los yog sib npaug li 0.02 hli | Siab -ceev ntau lawm: 300–400 pieces/min |
| Intelligent feeding system | Tsis siv neeg kho cov khoom siv sawb sib txawv ± 0.01 hli | Kev ua haujlwm tsis tu ncua tsis muaj sijhawm poob (4-teev kev ruaj ntseg) |
4. Stainless Hlau Hauv -Tuag Riveting
Raws li cov kws tshaj lij kev lag luam ntawm stainless hlau stamping qhov chaw thiab hauv -pwm riveting ntawm cov nyiaj tiv tauj hauv Suav teb, peb tau tsom mus rau qhov tseeb kev nce qib tuag stamping thiab kev koom ua ke hauv -pwm riveting tshuab rau nyiaj hu rau ntau tshaj 20 xyoo. Peb cov kev sib tw tseem ceeb yog cov hauv qab no:
4.1 Dual-Tau los ntawm Cov Khoom Siv thiab Cov Txheej Txheem
| Kev daws teeb meem | Txheej Txheem Zoo |
| SUS301 / SUS304 / SUS316 stainless hlau strips | Siab elasticity (SUS301 tensile lub zog Ntau dua los yog sib npaug rau 1200MPa) + corrosion kuj (SUS316 ntsev tshuaj tsuag ntau dua lossis sib npaug li 1000 teev) |
| Hauv -Mould Riveting Technology | Lub cev muaj zog sib txuas ntawm cov nyiaj sib cuag thiab cov hlau tsis muaj steel substrates, lub zog sib txuas Ntau dua los yog sib npaug rau 80MPa (ob zaug ntawm cov khoom siv vuam tsoos) |
4.2 Precision Progressive Tuag Stamping Technology
Tag Nrho -Txoj kev muaj peev xwm sib xyaw ua ke:
Ntau -chaw nres tsheb loj zuj zus tuag ua tiav kev xuas nrig ntaus, khoov, tsim, thiab riveting hauv ib qho mus (txo 3+ cov txheej txheem nruab nrab)
Micro-Riveted Cheebtsam ua muaj peev xwm (yam tsawg kawg nkaus feature loj 0.3mm, thickness 0.08 - 2.0mm)
Sib npaug ntawm Efficiency thiab Precision:
Automated pub system: sawb qhov tseeb ± 0.01mm
Kev ruaj ntseg ntawm siab- tshuab xuas nrig ntaus ceev: qhov tsis xws luag < 0.1% thaum lub sij hawm tas mus li ntawm 300 strokes ib feeb
4.3 Nto Kho Kev daws teeb meem
| Hom txheej txheem | Technical Effect | Kev xeem Standard |
| Nyiaj Plating | Tiv tauj tsis kam txo los ntawm 40% (tsawg dua los yog sib npaug rau 30μΩ), txhim kho hluav taws xob conductivity | Txheej thickness Ntau dua los yog sib npaug rau 5μm (kuaj los ntawm X-ray fluorescence spectrometry) |
| Nickel / Tin Plating | Anti- muaj peev xwm oxidation tau nce 3 zaug, kev ntsuas ntsev ntsev Ntau dua lossis sib npaug li 96 teev | Tsis tev tawm hauv cross- txiav adhesion xeem (ASTM D3359) |
| Laser ntxuav | Qhov saum npoo roughness Ra tsawg dua lossis sib npaug li 0.2μm, tshem tawm cov oxide zaj duab xis impurities | Tsis muaj residues tau pom nyob rau hauv 100x optical microscope |
4.4 Kev nce qib hauv -Mould Riveting Technology rau Nyiaj Tiv Tauj
(1) Kev sib piv ntawm cov txheej txheem txheej txheem
| Cov txheej txheem ib txwm ua | Hauv -Pwm Riveting txheej txheem | Core txawv |
| Vuam / Adhesive Bonding | Yuav tsum muaj cov txheej txheem ntxiv, kev pheej hmoo ntawm thermal deformation, thiab nplaum aging | Ua tiav synchronously thaum lub sij hawm stamping txheej txheem, tsis muaj ntxiv zog noj |
| Hauv -Pwm Riveting | Cold forming kev twb kev txuas los ntawm precision punches, lub cev metallurgical bonding | Hlau grain fusion ntawm qhov chaw sib txuas, lub zog tensile Ntau dua lossis sib npaug li 80MPa |
(2) Plaub Quadrant ntawm Technical Advantages
Mechanical Performance: Shear tsis kam ntawm riveting cov ntsiab lus Ntau dua los yog sib npaug rau 50N (thaum nyiaj tiv tauj specification yog φ2.0mm), tsis muaj loosening tom qab 100,000 vibration xeem
Hluav taws xob Conductivity: Tiv tauj tsis kam Tsawg dua los yog sib npaug rau 50μΩ (20% qis dua cov txheej txheem vuam), ntsuas kub nce ΔT Tsawg dua lossis sib npaug rau 30K
Kev Ua Tau Zoo: Ib qho - chaw nres tsheb sib koom ua ke txo 2 txheej txheem, 100% automation tus nqi, tawm los nce mus rau 99.5%
Kev ua raws li ib puag ncig: Tsis siv cov khoom siv hluav taws xob lossis cov nplaum nplaum, cov pa roj carbon emissions thaum lub sijhawm tsim khoom txo los ntawm 60%
Vim li cas thiaj xaiv peb?
1. Sib sib zog nqus cultivating kev lag luam rau 30 xyoo, kev daws teeb meem ncaj qha mus rau qhov mob cov ntsiab lus ntawm kev lag luam
Kev paub txog kev tsub zuj zuj:Cov pab pawg tseem ceeb los ntawm lub ntiaj teb cov tuam txhab ua lag luam hauv kev sib txuas lus, tsom mus rau kev sib txuas hluav taws xob rau 30 xyoo, ua tib zoo saib xyuas cov yam ntxwv ntawm cov khoom siv thiab cov txheej txheem tsis ua haujlwm ntawm cov khoom siv hluav taws xob tsawg, lub zog tshiab, thiab lwm yam xwm txheej, thiab tuaj yeem muab kev ua haujlwm zoo- txhim kho thiab nqi-txo cov cuab yeej siv thev naus laus zis - tsis pub dhau 4} (kev daws teeb meem thiab kev tsim kho tshiab) Sib cuag thiab Stampings, siab thermal conductivity vuam txheej txheem)
Tag nrho qeb manufacturing matrix:Feem ntau koom nrog riveting/welding silver contacts, tungsten copper contacts, relay cores, and more than 100 kinds of precision metal In-Die Rivet Electrical Contacts, adapting to traditional low-voltage electronics appliances such as circuit breakers and relays and emerging fields such as a new zog{3} kev pab cuam lub tsheb,
2. Kev pabcuam thoob ntiaj teb, cov lus teb sai los tsim tus nqi
Xya lub hauv paus loj thoob ntiaj teb:Layout Barcelona (Tebchaws Europe thiab Tebchaws Meskas), Tehran (Middle East), New Delhi/Port Klang (Southeast Asia), Tokyo (Nyiv thiab Kaus Lim Qab Teb), thiab lwm qhov chaw xaiv tsa, muab 24- teev hauv zos docking, kev them nyiaj yug thiab tom qab- cov lus teb muag, ua txhaum kev sib koom tes hla ciam teb
Agile shipping system:Cov qauv xa tuaj sai sai li ntawm 1-2 hnub, lub voj voog kev loj hlob yog compressed rau 20-30 hnub, thiab cov khoom xaj xaj xaj xa tuaj tsis pub dhau 15-20 hnub (kev tsim khoom tiav thaum tau txais cov nyiaj them poob haujlwm), raug txuam nrog cov neeg siv khoom R & D thiab cov khoom siv ntau lawm.
3. Vertical kev koom ua ke ntawm cov khoom lag luam, zoo, thiab tus nqi
Tag nrho cov txheej txheem kev koom ua ke: master 12 core processes such as cold stamping and laser welding, and realize full-process closed-loop production from raw materials to finished products, with a yield rate of >99.99%, thiab kev them nqi ntawm 10-15% qis dua li cov phooj ywg
Smart manufacturing pawg layout:txhua xyoo tso zis tus nqi ntawm lub zog tshiab yog 120 lab, txhua xyoo tso zis tus nqi qis -voltage cov khoom siv hluav taws xob yog 80 lab, peb lub hauv paus loj hauv Xiamen (tshiab zog stamping qhov chaw / nyiaj tiv tauj cov khoom / relay cores) + ob lub tuam txhab kev lag luam loj hauv Ningbo (pwm txoj kev loj hlob / kev ua tiav), tsim kev faib ua haujlwm ntawm kev ua haujlwm.
4. Tag nrho -dimensional quality assurance, international certification escort
Tag nrho cov txheej txheem zoo tswj:dhau IATF 16949 automotive-qib kev tswj xyuas qhov system ntawv pov thawj, kev ua raws li RoHS/REACH ib puag ncig cov qauv, tag nrho traceability los ntawm raw khoom tshuaj ntsuam xyuas (electrolytic tooj liab purity ntau dua los yog sib npaug rau 99.95%) kom tiav cov khoom kuaj
Cov ntaub ntawv-raws li kev tswj kom zoo:Muab cov ntaub ntawv muaj pes tsawg leeg (COA), thiab cov txheej txheem kev tswj xyuas cov ntaub ntawv (SPC) cov ntaub ntawv pob kom ntseeg tau cov khoom sib xws los ntawm cov qauv thoob ntiaj teb xws li UL thiab VDE
5. Hard-cov tub ntxhais txawj ntse tsim lub hauv paus, escorting loj - teev ntau lawm
Independent manufacturing system:7 lub rooj cob qhia kev tshaj lij (stamping / vuam / pwm, thiab lwm yam) yog 100% kev ua haujlwm ntawm nws tus kheej, nrog cov pob txha pob txha suav nrog ntau dua 30%, ua tiav xoom outsourcing ntawm cov txheej txheem tseem ceeb
Intelligent equipment cluster:Nruab nrog ntau pua lub siab-kawg cov cuab yeej (ntau- chaw nres tsheb txias taub hau tshuab / laser vuam robots, thiab lwm yam), lub peev xwm ua txhua xyoo ntau tshaj 1 billion daim, nrog rau ob qho tib si loj - nplai ntau lawm thiab siab- kawg customized tsim muaj peev xwm
tiv tauj peb
Cim npe nrov: Riveting Contact Assembly, Silver Contact Riveting, Sib cuag Riveted Assembly, Hluav Taws Xob Sib Txuas Sib Txuas, Nyiaj Rivet Hluav Taws Xob Kev Sib Txuas, Tooj Hauv -Tuag Riveting, Brass Stamping Silver Contact, Beryllium Copper Riveted Contact, Stainless Steel In-Tuag Riveting, Relay Contact Assembly Chaw tsim tshuaj paus
