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Seiko Case Material Codes Seiko Case Material Codes Seiko has used many different materials for watch cases over the years. These greatly expanded in the late 70's and 80's when a range of different case materials were tested and various materials were employed to utilize their specific properties. The different materials used in the watch case construction are detailed in product catalogs and are often indicated on the case itself.
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This listing was initially created from the 1991 Seiko JDM dealer catalog but additional items have been added. The abbreviation is the case material that is listed in the catalogs and the case back stamping is what is often but not always marked on the watch case back.
Here is an example of the case material codes from the 1991 Vol. 1 Catalog, e.g. SBBS018 has the case material code of THGMCETIHG, the SBBN001 has a code of TIHC.TI and the SSBT014 has TIHNT.TI.
The original 1991 listing from the JDM catalog can be downloaded from here - 1991 Seiko Case Codes JDM Catalog Vol1.pdf
See below for a table listing the various case material codes that have been used used.
Abbreviation
10KXS
Description
Case Back Stamping
Case of 10K yellow gold with reinforced inner
10K BASE ST.STEEL
body with SS
ST.STEEL BACK
10KYS
10K yellow gold case, SS case back
10K ST.STEEL BACK
14K.GP
14K yellow gold case, GP case back
14KT BASE METAL BACK
14KCE
Combined case with 14K yellow gold and
14KT + CERAMICS
ceramic
ST.STEEL BACK
Case of 14K yellow gold with reinforced inner
14K BASE ST.STEEL
body with SS
ST.STEEL BACK
14KYS
14K yellow gold case, SS case back
14K ST.STEEL BACK
18K
18K yellow gold case
18K (18KT)
18KWG
18K white gold case
18KT
18KYG
18K yellow gold case
18K (18KT)
AAPC
All Aluminum Palladium Alloy
AAPC
ABCRP
Black chrome plated case. Back lid black
BASE METAL
14KXS
chrome plating
ACRP
Chrome plated case. Back cover chrome
CRP
plating
AGF
All Gold Filled
AGF
AGPRUP
Ruthenium-plated on gold-plated case of the
BASE METAL
cast-in-tone. Back cover GPRUP
AHC
All Hard Coat, case coated with hard titanium
BASE METAL
nitride. Back cover HC
AHGC
Case coated with hard titanium nitride.
HGC
(Surface hardness or resistance to small scratches, Hv = 1200) Back side HCC
ALM
Rigid light alloy
ALM
ALSGP
All Light SEIKO Gold Colour Plated case
ALSGP
APDP
Case and case back with applied palladium
PDP
plating.
ASG
All SEIKO Gold Plated case
SGP
ASGP
Gold plating. Gold back plated
SGP
ASILVER
All Silver. SILVER 850 is difficult to tarnish
xxx SILVER or SILVER
(sulfide) uniquely developed by SEIKO, it is a
xxx
hard finish or fine silver
ASSGP
ATI
Part of stainless steel plated with gold.
ST.STEEL+ BASE
Partially gold-plated back cover
METAL
All Titanium case. (Excellent corrosion
TITANIUM
resistance and light weight) Backside Titanium.
ATIHC
Titanium case coated with hard titanium
TITANIUM
nitride. (Same for rear cover) (In addition to the features on the titanium side, it is strong in surface hardness or high scratch resistance. Hv = about 1200)
ATIHICDC
All TI case with super hard coating
TITANIUM
AWGF
All White Gold Filled
AWGF
AWGP
All White Gold Plating
AWGP
BCRP
Black chrome plated side. Back SS
BCRP ST.STEEL BACK
BCRP-PCD
Case combining black chrome plating and
BASE METAL+
plastic resin.
PLASTICS ST.STEEL BACK
BTIHC.MBTIHC
All high intensity titanium
TITANIUM
CE
Ceramic Case (hard highly scratch resistant,
CERAMICS ST.STEEL
Hv = 1500, no rusting, with a beautiful surface)
BACK
**
CEAC
Case where the ceramic was coated with hard
CERAMICS ST.STEEL
titanium nitride.
BACK
Part ceramic on which the coating of hard
CERAMICS ST.STEEL
titanium nitride was applied.
BACK
CRP
Chrome plated case.
CRP ST.STEEL BACK
FRC
Blowing fluorocarbon resin to the lower side of
BASE METAL
the coating.
ST.STEEL BACK
CEHGC
FRC.PCD
Fused case combined resin coating and plastic
BASE METAL+
resin.
PLASTICS ST.STEEL BACK
FRP
Fibre Reinforced Plastic
PLASTIC
GC
Gold Cap
GC
GF
Case affixed with gold.
GOLD FILLED ST.STEEL BACK
GHA
Case coated with hard titanium nitride.
GHA ST.STEEL BACK
(Surface hardness is high resists against small scratches. Hv = 1200).
GPBCR
Gold plated and black chrome plated case.
BASE METAL ST.STEEL BACK
GPCRP
Gold plated and chrome plated case.
BASE METAL ST.STEEL BACK
GPCRP.GP
Gold plated and chrome plated case. Back side GP
BASE METAL
GPDP
Case combining gold and palladium plating.
SGP + PDP ST.STEEL BACK
GPDP.GP
Case combining gold and palladium plating.
SGP + PDP SGP BACK
Back cover GP
GPHC
GPHGC
GPRUP
GPWD
HC
Case combining hard coating of titanium
BASE METAL
nitride.
ST.STEEL BACK
Case combining hard coating of titanium
BASE METAL
nitride and gold plating.
ST.STEEL BACK
Case on which the ruthenium plating was
BASE METAL
applied on the gold plating.
ST.STEEL BACK
Gold-plated case, combined with reinforced
BASE METAL + WOOD
wood.
ST.STEEL BACK
Case coated with hard titanium nitride.
BASE HC ST.STEEL
(Surface hardness or resistance to small
BACK
scratches, Hv = approximately 1200)
HC.SSHC
HC bezel and middle with combined SS and
BASE HC ST.STEEL
HC back
BACK HC
HCBCRP
Coating of hard titanium nitride and the side
BASE METAL
subjected to black chrome plating.
ST.STEEL BACK
HGC
Case coated with hard titanium nitride.
HGC ST.STEEL BACK
HGCPC
Case combined with plastics by applying a
HGC + PLASTICS
coating of hard titanium nitride.
ST.STEEL BACK
Hard gold plated case. (Surface hardness is
HGP ST.STEEL BACK
HGP
high and resistant to small scratches. Hv = about 500)
HSS
Case made of hard stainless steel. (Hv = about STAINLESS STEEL 450)
HTIAGP.HTIA
Part of the hard titanium alloy on the case
TITANIUM ALLOY
plated with gold
LSGP
Light colour SGP
SGP
MCOA
Cobalt hard alloy case. (Excellent in corrosion
COBALT ALLOY
resistance and strong against small scratches.
ST.STEEL
Hv = 500) Edge / Back SS
BEZEL.BACK
MHC
SS case coated with hard titanium nitride.
BASE METAL ST.STEEL BEZEL, BACK
MSS.HC
SS middle with hard titanium nitride bezel and
ST.STEEL + BASE
back
METAL ST.STEEL BEZEL
MSSGP
Case of SS plated with gold
ST.STEEL + BASE METAL ST.STEEL BEZEL,BACK
MSSPCD
MTIGLC
SS bezel combined SS and plastic middle with
PLASTICS ST.STEEL
SS back
BEZEL
Titanium coated with glass (surface hardness
TITANIUM ST.STEEL
is higher than ordinary titanium, Hv = about
BEZEL,BACK
350-400) and SS.
NSA
Super hard alloy side. (Surface hardness is
NSA STEEL BACK
high and resistant to small scratches, Hv = about 1200). **
NSACG
A part of the superhard alloy was coated with
NSA+NSCG ST.STEEL
hard titanium nitride. **
BACK
NSAG
Super hard alloy case. (Surface hardness is
NSAG ST.STEEL BACK
high and resistant to small scratches, Hv = about 1200). **
NSAGCE
NSB
On the part of the case where the super hard
TUNGSTEN CARBIDE
alloy and ceramic are combined the coating of
+ CERAMICS
hard titanium nitride was applied. **
ST.STEEL BACK
The case sprayed with hard material such as
NSB ST.STEEL BACK
ceramic. (Surface hardness is high and resistant to small scratches, Hv = about 7001000).
NSCG
Case of super hard alloy coated with hard
NSCG ST.STEEL BACK
titanium nitride. (Surface hardness is high and resistant to small scratches, Hv = about 1200). **
NSCGCE
The case combining hard carbide and hard
TUNGSTEN CARBIDE
ceramic with hard titanium nitride. (Surface
+ CERAMICS
hardness is high and resistant to small
ST.STEEL BACK
scratches. Hv = about 1200)
NSP
Hard Alloy Processing
NSP
PC
Case made of plastic.
PLASTICS
PC.SS
Case made of plastic. Case back SS
PLASTICS ST.STEEL BACK
PDP
Case subjected to bare Palladium plating.
PDP ST.STEEL BACK
PDPRUP
Ruthenium plated case on palladium plating.
BASE METAL ST.STEEL BACK
PM
Platinum
PM
PMP
Platinum Plating
PMP
SGP
Seiko Gold Colour Plate.
BASE METAL ST.STEEL BACK
SGP30
Case with 30 micron gold plating.
SGP30 ST.STEEL BACK
SHA
Hard alloy case. (Hv = about 700).
SHA ST.STEEL BACK NICKEL ALLOY ST.STEEL BACK
SHAGHA
A part of the hard alloy case is coated with
NICKEL ALLOY
hard titanium nitride.
ST.STEEL BACK
SHAHC
A part of the hard alloy case is coated with
NICKEL ALLOY
hard titanium nitride.
ST.STEEL BACK
SILP
Silver Plating
SILP
SILVER
Case made of silver. xxx represents value of
xxx SILVER ST.STEEL
silver / 1000
BACK or SILVER xxx ST.STEEL BACK
SS
Case made of stainless steel. It is harder to
STAINLEES STEEL
rust than regular steel
SS.PCD
Part of SS with plastic decorations.
ST.STEEL+ PLASTICS ST.STEEL BACK
SS18K
SSBCR.BCRP
Case of 18K yellow gold and stainless steel
ST.STEEL + 18KT
combined.
ST.STEEL BACK
Case of the ss plus black chrome plating. Back
ST.STEEL+ BASE
cover black chrome plating.
METAL BASE METAL BACK
SSGP
Case of SS with gold plate
ST.STEEL+ SGP ST.STEEL BACK
SSGP.G
Case plated gold on part of SS. Ruptured Gold
ST.STEEL+ BASE
Plating.
METAL BASE METAL BACK
SSHC
Part of ss coated with hard titanium nitride.
ST.STEEL+ BASE METAL ST.STEEL BACK
SSPCD.BCRP
Apply black chrome plating to part of SS, case
ST.STEEL+
plated with plastic decoration.
PLASTICS+ BASE METAL ST.STEEL BACK
SSPCD.FRC
Fluorocarbon resin was sprayed on a part of
ST. STEEL + BASE
SS and the case on which plastic decoration
METAL MIDDLE BASE
was attached.
METAL BEZEL ST.STEEL BACK
SSWD
SS case combined with reinforced wood.
ST.STEEL WOOD ST.STEEL BACK
STP
Stainless Steel Plating
STP
T14K.M14KWG
Case combining 14K yellow gold and white
14KT ST.STEEL BACK
gold
T14KHC.M14K
Case of 14K gold yellow gold coated with hard
14KT ST.STEEL BACK
titanium nitride
T18K
Case which combines 18K yellow gold and SS
ST.STEEL 18KT BEZEL
T18K.MSS18K
Case with 18K yeloow gold and SS
ST.STEEL+ 18KT MIDDLE 18KT BEZEL ST.STEEL BACK
T18K.MSSGP
Combined 18K yellow gold and SS with some
ST.STEEL + BASE
gold plating
METAL MIDDLE 18KT BEZEL ST.STEEL BACK
TALH.MBCRP
Hard aluminum case combined with black
BASE METAL MIDDLE
chrome plating.
ALUMINIUM BEZEL ST.STEEL BACK
TALH.MFRC
A coating of fluororesin was applied to the
BASE METAL MIDDLE
case combined with hard aluminum.
ALUMINIUM BEZEL ST.STEEL BACK
TALH.NSB
Case where the hard material was sprayed
NSB MIDDLE ALH
and hard aluminum was combined.
BEZEL ST.STEEL BACK
TALM.MPC
Case on which aluminum and plastic are
PLASTICS MIDDLE
combined.
ALUMINIUM BEZEL ST.STEEL BACK
TALM.MPCPDP
Palladium plating on case combined with
PLASTICS MIDDLE
aluminum.
ALUMINIUM BEZEL ST.STEEL BACK
TBCRP
Part of SS was subjected to black chrome
ST.STEEL BASE
plating.
METAL BEZEL
TBCRP.FRC.MBCRP Black chrome plating and case with fluorinated
TBCRP.MFRC
TBCRP.MHC
TCE
BASE METAL
resin coating.
ST.STEEL BACK
Black chrome plating and case with fluorinated
BASE METAL
resin coating.
ST.STEEL BACK
The coating of hard titanium nitride and the
BASE METAL
case subjected to black chrome plating.
ST.STEEL BACK
Ceramic and SS combined case
ST.STEEL CERAMICS BEZEL
TCE.GP
Ceramic bezel, GP case
BASE METAL CERAMICS BEZEL
TCE.MTIHICDC
TCE.TIHC
TFRC
Ceramic bezel, TI with super hard coating
TITANIUM + CERAMIC
case and back
BEZEL
Ceramic bezel, TI with super hard coating
TITANIUM + CERAMIC
case and back
BEZEL
Part of SS was sprayed with fluorocarbon resin
ST.STEEL BASE METAL BEZEL
TFRC.MHC
TGP.MCOA
Case coated with fluororesin and hard nitride
BASE METAL
nitride
ST.STEEL BACK
Case with gold plated bezel and cobalt hard
COBALT ALLOY
alloy are combined
MIDDLE BASE METAL BEZEL ST.STEEL BACK
TGP.MGPBCRP
Black chrome plated and gold plated case
BASE METAL ST.STEEL BACK
TGP.MGPDP
TGP.MGPHC
Case with gold plated bezel and palladium
BASE METAL
plating
ST.STEEL BACK
SGP bezel, SGP and HC case
BASE METAL ST.STEEL BACK
TGP.MGPWD
Case combined with reinforced wood with gold
BASE METAL WOOD
plating
MIDDLE BASE METAL BEZEL ST.STEEL BACK
TGP.MHC
TGP.MHSS
Case gold plated bezel and hard titanium
BASE METAL
nitride case
ST.STEEL BACK
Hard stainless steel with gold plated bezel
ST.STEEL BASE METAL BEZEL
TGP.MSSGP
SGP bezel, combined SS and SGP middle
ST.STEEL BASE METAL BEZEL
TGP.TIHCCE
TGPCE.MGP
SGP bezel, combined TI, HC, and Ceramic
ST.STEEL SGP + SGP
one piece case
BEZEL
Combined SGP and Ceramic bezel, SGP case
BASE METAL CERAMICS BEZEL
TGPDP
Parts of SS plated with gold and palladium
ST.STEEL SGP + PDP
plating
BEZEL
TGPDP.G
Gold plated and palladium plated case
SGP MIDDLE SGP + PDP BEZEL ST.STEEL BACK
TGPDP.PD
Gold plated and palladium plated case
PDP MIDDLE SGP + PDP BEZEL ST.STEEL BACK
TGPGHA.MGHA
Gold plated case combined with hard material
NICKEL ALLOY MIDDLE BASE METAL + NICKEL ALLOY BEZEL ST.STEEL BACK
TGPHSS.MHSS
Case of hard SS with gold plating
ST.STEEL + BASE METAL BEZEL
TGPHTI.HTI
Rigid titanium case. (Ti alloy hardness was
TITANIUM ALLOY
improved in addition to the characteristics of
BASE METAL +
titanium having excellent lightness, ru
TITANIUM ALLOY
corrosion resistance, Hv = 300) case with gold
BEZEL
plating
TGP-MTI
Case combining titanium and gold plated bezel
TITANIUM MIDDLE BASE METAL ST.STEEL BACK
TGPSHA.MSHA
Gold plated hard nickel alloy
NICKEL ALLOY MIDDLE BASE METAL + NICKEL ALLOY BEZEL ST.STEEL BACK
TGPTI.TI
THC
THC.BTI
Combined TI and SGP bezel, TI middle and TI
TITANIUM + SGP
back
BEZEL
Case of SS coated with hard titanium nitride
ST.STEEL BASE
film
METAL BACK
HC bezel, BTI (Bright Titanium) middle and
TITANIUM
BTI back
THC.MBCRP
THC.MHCPCDP
Coating of hard titanium nitride and case
BASE METAL
subjected to black chrome plating
ST.STEEL BACK
HC bezel, combined HC and plastic middle
ST.STEEL + PLASTICS
with SS back
THC.MSHAC
Hard cobalt alloy case subjected to coating of
COBALT ALLOY
hard titanium nitride, case parts with hard
MIDDLE BASE METAL
titanium nitride coating
BEZEL ST.STEEL BACK
THC.MSSCE
THC.MTIGLC
THC.TIHCCE
HC bezel, combined SS and Ceramic middle,
CERAMICS +
and SS back
TITANIUM
Titanium coated with glass (surface hardness
TITANIUM MIDDLE
is higher than ordinary titanium, Hv = about
BASE METAL BEZEL
350-400) and SS with nitride coating.
ST.STEEL BACK
Ceramic Outer Case, TI HC Inner Case
CERAMICS + TITANIUM
THCHSS.MHSS
THGC
Ferrite hard stainless steel coated with rigid
ST.STEEL ST.STEEL +
titanium nitride
BASE METAL BEZEL
SS case coated with hard titanium nitride
ST.STEEL BASE METAL BEZEL
THGC.MCOAHGC
Cobalt hard alloy case coated with hard nitride
COBALT ALLOY MIDDLE BASE METAL BEZEL ST.STEEL BACK
THGC.MHTI
Case combining SS with hard titanium nitride coating on rigid titanium (Rigid Ti = hardness more than ordinary Ti, Hv = about 300)
ST.STEEL + TITAN
THGMCETIHG
Combination of titanium and ceramics which
CERAMICS MIDDLE
was coated with hard titanium nitride
BASE METAL BEZEL TITANIUM BACK
THGMCETIHG
HGC bezel, combined Ceramics, TI and HGC
CERAMICS +
middle and combined Ceramics, TI and HGC
TITANIUM
back
THGP
Case of SS on which hard gold plating was
ST.STEEL HGP BEZEL
applied
THTIGP.HTI
Case of hard titanium coated with hard
TITANIUM ALLOY
titanium nitride
TI
Titanium
TITANIUM
TIHC.TI
Case of titanium coated with hard titanium
TITANIUM
nitride
TIHNT.TI
Titanium case which has been hardened by
TITANIUM
nitriding treatment. (Hv = about 600, Matte finish)
TPCBCRP.MBCRP
Black chrome plated case combined with
BASE METAL MIDDLE
plastic.
PLASTICS + BASE
METAL BEZEL ST.STEEL BACK
TPCFRC.MFRC
Fluorocarbon resin coating was applied and
BASE METAL MIDDLE
the case combined with plastic
PLASTICS + BASE METAL BEZEL ST.STEEL BACK
TPCS
Plastic and SS combined case
ST.STEEL PLASTIC BEZEL
TPDP
PDP bezel, SS case
PDP BEZEL + ST.STEEL
TPDP.G
Gold plated and palladium plated case
BASE METAL ST.STEEL BACK
TPDP.GPD
Gold plated and palladium plated case
BASE METAL ST.STEEL BACK
TPDP.MPDPHC
TSGP
Palladium plating and case coated with rigid
BASE METAL
titanium
ST.STEEL BACK
Case of SS plated with gold
ST.STEEL SGP BEZEL
TSGP.GPD
Palladium plating and gold plated case
BASE METAL MIDDLE SGP30 BEZEL ST.STEEL BACK
TSGP.PD
Gold plated and palladium plated case
PDP MIDDLE SGP BEZEL ST.STEEL BACK
TSGP.SSG
Case of SS with gold plating
ST.STEEL+ SGP MIDDLE SGP BEZEL ST.STEEL BACK
TSHA
Case combining hard alloy and SS
ST.STEEL NICKEL ALLOY BEZEL
TSS.PCA
Case combining SS and plastic
PLASTICS ST.STEEL BACK
TSSCE
TSSGP
Combined SS and Ceramic bezel , SS middle
ST.STEEL ST.STEEL +
and SS back
CERAMIC BEZEL
Case of SS with gold plated bezel
ST.STEEL ST.STEEL + SGP BEZEL
TSSGP.MGP
Case of SS with gold plated bezel
BASE METAL MIDDLE ST.STEEL + BASE
METAL BEZEL ST.STEEL BACK
TSSGP.MPDP
Combination of gold plated bezel and
BASE METAL MIDDLE
palladium plated case
ST.STEEL + BASE METAL BEZEL ST.STEEL BACK
TSSHC
TSSHC.HICDC
TTIGLCGP.MTIGLC
SS bezel coated with hard titanium nitride, SS
ST.STEEL ST.STEEL +
case
BASE METAL BEZEL
SSHC bezel, SS with super hard coating, and
ST.STEEL ST.STEEL +
SS with super hard coating back
ST.STEEL BEZEL
Titanium coated with glass (It has a higher
TITANIUM MIDDLE
surface hardness than ordinary titanium Hv =
TITANIUM + BASE
about 350-400) gold plate applied
METAL BEZEL ST.STEEL BACK
TTIHC.MTIHICDC.TI
Ti & HC bezel, Ti & HC middle, Ti Back
TITANIUM
TTIHC.TI
Combined TI and HC bezel, TI middle and TI
TITANIUM
back
TTUCAC
TTUCAC.MGP
Hard alloy coated with hard titanium nitride
ST.STEEL TUNGSTEN
combined with SS case
CARBIDE BEZEL
Case combining a super hard alloy plated with
BASE METAL MIDDLE
hard titanium nitride and gold plating
TUNGSTEN CARBIDE BEZEL ST.STEEL BACK
TUCAC
Case of the super hard alloy coated with hard
TUNGSTEN CARBIDE
titanium nitride (High surface hardness and
ST.STEEL BACK
resistant to small scratches, Hv = about 1200) **
TUCAC.SSGP
Case combining SS with a gold plate and a
TUNGSTEN CARBIDE
hard tungsten alloy coated with a hard titanium
+ ST.STEEL + BASE
nitride
METAL ST.STEEL BACK
TUCSS
Case combining SS with super hard alloy
TUNGSTEN CARBIDE
coated with hard titanium nitride
+ ST.STEEL ST.STEEL BACK
TWGP
White gold plated bezel with stainless steel
TWGP
case
WGF
White Gold Filled
WGF
WGP
White Gold Plating
WGP
WGPG
Gold plated case with gold-plated bezel
WGPG
Note **: Although it is hard to scratch it is slightly brittle so care should be taken to avoid shocks such as a drop.
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