2024 ABUS Top 20 Bike Locks for sale

• #1

  

  ABUS

  Bordo 5700, Folding lock-Blue

  £69.99

  #5700/80 blue
• #2

  

  ABUS

  Pro Amparo 4750SL R BK Bicycle Frame Lock with Lock Housing for Connecting Chains Key Not Removable When Lock Open - Security Level 9

  £30.08

  #89679

  Road lock: the bicycle lock is firmly mounted, so that when closed a latch blocks the spokes - the wheel cannot be easily pushed away|Material: Shackle, housing and supporting parts of the locking mechanism are made of specially hardened steel|R version: key can only be removed when the lock is locked, so the key cannot be lost or forgotten (2 keys included)|Details: spoke lock with ABUS safety level 9 - 85 mm thick locking bolt, weight 700 g, max Mudguard width: 75 mm, max Tyre width: 56 mm, max Flow height: 106 mm|Chain connection: optionally available plug-in chain or a cable can be inserted into the lock housing of the frame lock - when locking, both are locked

• #3

  

  ABUS

  1360 / 85 AB42935, Nero, 85 cm

  £34.39

  #AB136085

  Abus contribuisce responsabilmente alla protezione delle persone e degli oggetti di valore, occupandosi, in molti campi della vita, di questo vantaggio e sicurezza

• #4

  

  ABUS

  BORDOLite 6055, Antifurto Pieghevole Unisex Adulto, Nero, Unica

  £73.98

  #A1621048

  Light and stable: Folding lock in a convenient transport size with rods made of lightweight materials and steel alloys|Foldable and compact: The special rivets allow flexible folding of the lock into a handy/compact size, perfect for athletes|Automatic cylinder: Active locking is no longer needed, simply insert the rod into the lock body and a click confirms locking|Details: Bordo Lite 6055K/85: length 85 cm, weight 500 g, incl 2 keys, ABUS security level 7, good protection for low to medium theft risk|SR bracket: Specially designed lock bracket for mounting under Selle Royal saddles, space-saving and perfect for athletes

• #5

  

  ABUS

  7210 / 85, Lucchetto a Catena. Unisex-Adulti, 0, 85 centimetri

  £30.06

  #87777 3

  7mm thick square chain with functional, durable and highly flexible synthetic fiber coating to protect against paint damage|The coating offers high abrasion protection and does not absorb liquids, such as water or oil|The chain, housing and bearing parts of the locking mechanism|The 7 mm thick chain ensures high theft safety|The soft case protects your frame from damage

• #6

  

  ABUS

  frame lock plug-in chain - Adaptor Chain 2.0 6KS - chain for secondary bicycle security - 6 mm thick - 100 cm long - black - with lock bag 5950

  £43.89

  #95363

  FUNCTION: Plug-in chains allow bicyle fitted with frame locks or Alrambox 20 to be securely locked to lampposts, bike racks etc|HOW TO USE: Place the chain around a fixed object, pull the chain through the ring on the chain and insert it into the lock housing of the frame lock or the Alarmbox 20 - without an additional key|STRONG: 6 mm thick square chain made of hardened steel - to protect against bicycle thieves|SCRATCH PROTECTION: Plastic coating on the chain protects against scratches and damage to the paintwork|FEATURE 20: In the 20 version, the loop ring is coated to protect from scratches|LOCK BAG 5950: for convenient transportation of the chain under the saddle - attaches with the help of Velcro straps - 06 l stowing capacity - water-repellent material - included in delivery|DETAIL...

• #7

  

  ABUS

  Champ 8700 / 85 Cord Lock

  £31.12

  #61885

  Extremely stable|Length: 85 cm|Diameter: 20 mm

• #8

  

  ABUS

  8808C / 110 BK Lucchetto, Adulti Unisex, Nero (Rosso), Taglia Unica

  £63.35

  #A8614941

  Use: Bike lock with ABUS security level 9 out of 15, good protection for bikes with medium risk of theft|Chain: 8 mm thick square chain made of specially hardened steel|Number code: 4-digit number combination is individually adjustable Number rollers made of 2 components ensure permanent legibility of numbers|Product details: Combination lock 8808C/110: length 110 cm, weight 2766 g, chain thickness 8 mm, colour black

• #9

  

  ABUS

  Foldable Lock Bordo Granit XPlus 6500 / 85 ST with Lock Bag, Hardened Steel Bike Lock, Security Level 15, 85 cm, Black & Sh 6500 / 85 Bordo Xplus Staffa 2018.

  £114.21

  Product 1: Recommended for securing high quality bicycles|Product 1: 55 mm Steel bars with extra soft two components coating to prevent damage to the bicycle's paintwork|Product 1: Colour-matching silicone cover for the lock body with soft touch properties|Product 1: Link construction offers compact folding|Product 2: 2018|Product 2: Requires little space, as the lock can be removed at the front|Product 2: Ideal for small frames

• #10

  

  ABUS

  Granit XPlus 540 U-Lock 160HB300 Anti-Theft, 300 mm + USH540 & Cobra Cable

  £101.37

  Product 1: 13 mm, hardened steel square parabolic shackle|Product 1: ABUS power cell technology offers highest protection against hitting and pulling attacks|Product 1: The shackle, the case as well as supporting elements of the locking mechanism are made of special hardened steel|Product 1: ABUS XPlus cylinder for highest protection against manipulations, eg picking|Product 2: Every year millions of bikes are stolen|Product 2: Police statistics show that only about ten percent of these cases are solved|Product 2: It doesn't have to be like that, as ABUS covers the whole range of bike security devices with high-quality locks|Product 2: ABUS offers the right bike lock for every situation

• #11

  

  ABUS

  14KS 6' Maximum Security Square Chain and Sleeve, 9 / 16" Diameter Chain Link

  £434.32

  #14KS 6' Chain and Sleeve

  High Security Chain: This security chain offers optimum security against all types of aggressive attacks Made of hardened steel with a special anti corrosion coating that makes them ideal for outdoor use|Anti Theft Design: This chain features square shaped links, much more effective against attacks with tools The chains also feature a nylon sleeve to prevent scratches and damage to paint work and chrome|Padlocks for Any Application: Discover the variety of our padlocks, from heavy duty Granit padlocks and disc locks to brass, steel and aluminum models, to resettable combination, rekeyable and keyed alike locks|The World's Leading Security Manufacturer: We offer a comprehensive line of home, commercial security and worker safety products including padlocks and hasps, chains and cables, key...

• #12

  

  ABUS

  5700 / 100 BU Sh, Lucchetto Pieghevole. Unisex-Adulti, Blu, 100 cm

  £66.98

  #86744 6

  Il modello versatile con livello di sicurezza 7: il lucchetto pieghevole alla moda con barre spesse 5 mm, il cilindro automatico di alta qualità e la pratica modalità di trasporto offrono protezione in caso di rischio di furto basso e medio|Adattabile individualmente: questo modello è disponibile in numerose varianti di colore e può quindi essere utilizzato per ad esempio possono essere adattati visivamente al casco o alla bicicletta|Pieghevole e compatto: i rivetti speciali consentono di piegare la serratura in modo flessibile e di ottenere una dimensione pratica e quindi un trasporto leggero e salvaspazio|Lucchetto antifurto per biciclette: lunghezza 100 cm, peso 1050 g, livello di sicurezza 7, con supporto e 2 chiavi|Sicuro, affidabile e stabile Questo è il nome ABUS Che si tratti...

• #13

  

  ABUS

  87786 SmartX RC OEM Frame Locks, Unicolor, one Size

  £61.58

  #87786

  High-quality ABUS product|Model Number: 87786|Material: Aluminium

• #14

  

  ABUS

  4804C, Lucchetto Unisex, Rosso, 75 cm, Red

  £21.50

  #724688

  Item Package Quantity: 1|Model Number: 724688|Package Weight: 360 grams|Colour: red

• #15

  

  ABUS

  Folding Lock Bordo 6000K with Saddlefix Mount and Rain Cover, Bike Lock with XPlus Cylinder for Strong Tamper Protection, Security Level 10, Length 90 cm

  £89.99

  #67865

  Safe and flexible: Foldable bicycle lock with ABUS security level 10, good protection to safeguard against medium theft risk|Solid: 5 mm thick rods and housing made of specially hardened steel The rods are connected by special rivets|Product details: Bordo 6000K/90: length 90 cm (when unfolded), width 64 mm, weight 1207 g, colour black, includes 2 keys, rain cover and bracket|Coating: Folding lock with extra soft and resistant coating on the bars and housing to protect against paintwork damage and provide a good grip

• #16

  

  ABUS

  HB140 - Lucchetto per bicicletta Unisex per adulti, 420 / 150HB140 + USH Ultimate, Black, 14 cm

  £39.13

  #A9816895

  Robusto, compatto e resistente al picking: serratura a U con cilindro di alta qualità per proteggere da manomissioni come ad esempio picking – bloccaggio e sblocco con chiave|Con staffa rotonda da 13 mm in acciaio temprato: alloggiamento, staffa e parti portanti del meccanismo di bloccaggio sono realizzati in acciaio temprato|Design moderno e accattivante, facile da usare grazie al rivestimento del corpo del lucchetto|Lucchetto affidabile per bicicletta e bicicletta elettrica di alta qualità: spessore 13 mm, peso 900 g, altezza 140 mm, larghezza 80 mm, livello di sicurezza ABUS 12, con 2 chiavi e supporto USH|Sicuro, affidabile e stabile Questo è il nome ABUS Che si tratti di protezione a casa, di sicurezza degli oggetti o di sicurezza mobile: ABUS definisce gli standard

• #17

  

  ABUS

  32869 Antivol U 58 HB3 100 avec Chaine 12KS 80 cm Loop Homologués SRA Noir, Black

  £132.23

  #32869

  Package Weight: 442 kilograms|Package Dimensions: 50 L x 532 H x 174 W (centimetres)|Very Convenient|Easy to use

• #18

  

  ABUS

  Bicycle Lock 5510 K 14245 1 / 180 / 10 Bk S cmu, One Size, Unisex, Fahrradschloss, Red

  £21.14

  #14473-8

  ABUS contributes in a responsible way to the protection of people and valuables, taking care, in many fields of life, of that plus in security|10 mm thick, high-quality and super flexible spiral cable|Plastic coating to prevent damage to the bicycle’s paintwork|Good protection at low theft risk

• #19

  

  ABUS

  78062 - Lucchetto pieghevole Bordo Lite Mini 6055 / 60 – Extra leggero in acciaio speciale – Livello di sicurezza 7 – 60 cm, Blue

  £42.98

  #78062-2

  Il nostro modello minimalista con livello di sicurezza 7: lucchetto pieghevole compatto e comodo da trasportare con barre in materiali leggeri e leghe di acciaio per una particolare flessibilità e mobilità|Pieghevole e compatto: i rivetti speciali consentono di piegare la serratura in modo flessibile e di ottenere una dimensione pratica e quindi un trasporto leggero e salvaspazio|Piccolo, maneggevole e alla moda: il lucchetto protegge in modo affidabile dai danni alla vernice come ad esempio graffi sulla bicicletta|Lucchetto antifurto per biciclette: lunghezza 60 cm, peso 400 g, livello di sicurezza 7, con 2 chiavi incluse|Sicuro, affidabile e stabile Questo è il nome ABUS Che si tratti di protezione domestica, sicurezza degli oggetti o sicurezza mobile: ABUS definisce gli standard

• #20

  

  ABUS

  Goose Lock chain lock - bendable, rattle-free bicycle lock made of hardened steel - 6 mm thick - 110 cm long - with key - security level 7 - blue

  £65.11

  #955471

  SHAPE KEEPER: holds its shape thanks to gooseneck technology,yet flexible at the same time and wraps round the bicycle frame during transport without rattling|SOFT TOUCH: functional, durable, highly flexible coating made of synthetic fibres combined with an underlying foam cover provides a pleasant feel and offers protection against wear|AREA OF APPLICATIONS: for securing bicycles and scooters, suitable for indoor and outdoor use|LOCKING TYPE: two keys included|SECURE: ABUS security level 7 - solid protection for medium theft risk - chain, housing and supporting parts of the locking mechanism are made of specially hardened steel|PRODUCT DETAILS: 6 mm thick and 110 cm long chain with dimensionally stable components and soft coating, chain made of specially hardened steel

UK ABUS Bike Locks

• 
  £69.99

  ABUS Bike Locks

  Bordo 5700, Folding lock-Blue

  #5700/80 blue
• 
  £30.08

  ABUS Bike Locks

  Pro Amparo 4750SL R BK Bicycle Frame Lock with Lock Housing for Connecting Chains Key Not Removable When Lock Open - Security Level 9

  #89679

  Road lock: the bicycle lock is firmly mounted, so that when closed a latch blocks the spokes - the wheel cannot be easily pushed away, Material: Shackle, housing and supporting parts of the locking mechanism are made of specially hardened steel, R version: key can only be removed when the lock is locked, so the key cannot be lost or forgotten (2 keys included), Details: spoke lock with ABUS safety level 9 - 8. 5 mm thick locking bolt, weight 700 g, max. Mudguard width: 75 mm, max. Tyre width: 56 mm, max. Flow height: 106 mm, Chain connection: optionally available plug-in chain or a cable can be inserted into the lock housing of the frame lock - when locking, both are locked

• 
  £34.39

  ABUS Bike Locks

  1360 / 85 AB42935, Nero, 85 cm

  #AB136085

  Abus contribuisce responsabilmente alla protezione delle persone e degli oggetti di valore, occupandosi, in molti campi della vita, di questo vantaggio e sicurezza

• 
  £73.98

  ABUS Bike Locks

  BORDOLite 6055, Antifurto Pieghevole Unisex Adulto, Nero, Unica

  #A1621048

  Light and stable: Folding lock in a convenient transport size with rods made of lightweight materials and steel alloys, Foldable and compact: The special rivets allow flexible folding of the lock into a handy/compact size, perfect for athletes, Automatic cylinder: Active locking is no longer needed, simply insert the rod into the lock body and a click confirms locking, Details: Bordo Lite 6055K/85: length 85 cm, weight 500 g, incl 2 keys, ABUS security level 7, good protection for low to medium theft risk, SR bracket: Specially designed lock bracket for mounting under Selle Royal saddles, space-saving and perfect for athletes

• 
  £30.06

  ABUS Bike Locks

  7210 / 85, Lucchetto a Catena. Unisex-Adulti, 0, 85 centimetri

  #87777 3

  7mm thick square chain with functional, durable and highly flexible synthetic fiber coating to protect against paint damage, The coating offers high abrasion protection and does not absorb liquids, such as water or oil, The chain, housing and bearing parts of the locking mechanism, The 7 mm thick chain ensures high theft safety, The soft case protects your frame from damage

• 
  £43.89

  ABUS Bike Locks

  frame lock plug-in chain - Adaptor Chain 2.0 6KS - chain for secondary bicycle security - 6 mm thick - 100 cm long - black - with lock bag 5950

  #95363

  FUNCTION: Plug-in chains allow bicyle fitted with frame locks or Alrambox 2. 0 to be securely locked to lampposts, bike racks etc, HOW TO USE: Place the chain around a fixed object, pull the chain through the ring on the chain and insert it into the lock housing of the frame lock or the Alarmbox 2. 0 - without an additional key, STRONG: 6 mm thick square chain made of hardened steel - to protect against bicycle thieves, SCRATCH PROTECTION: Plastic coating on the chain protects against scratches and damage to the paintwork, FEATURE 2. 0: In the 2. 0 version, the loop ring is coated to protect from scratches, LOCK BAG 5950: for convenient transportation of the chain under the saddle - attaches with the help of Velcro straps - 0. 6 l stowing capacity - water-repellent material - included in delivery, DETAILS: 6 mm thick and 100 cm long connecting chain for frame locks incl. lock bag, weight indication for lock incl. bag

• 
  £31.12

  ABUS Bike Locks

  Champ 8700 / 85 Cord Lock

  #61885

  Extremely stable. , Length: 85 cm. , Diameter: 20 mm

• 
  £63.35

  ABUS Bike Locks

  8808C / 110 BK Lucchetto, Adulti Unisex, Nero (Rosso), Taglia Unica

  #A8614941

  Use: Bike lock with ABUS security level 9 out of 15, good protection for bikes with medium risk of theft, Chain: 8 mm thick square chain made of specially hardened steel, Number code: 4-digit number combination is individually adjustable Number rollers made of 2 components ensure permanent legibility of numbers, Product details: Combination lock 8808C/110: length 110 cm, weight 2766 g, chain thickness 8 mm, colour black

• 
  £114.21

  ABUS Bike Locks

  Foldable Lock Bordo Granit XPlus 6500 / 85 ST with Lock Bag, Hardened Steel Bike Lock, Security Level 15, 85 cm, Black & Sh 6500 / 85 Bordo Xplus Staffa 2018.

  Product 1: Recommended for securing high quality bicycles, Product 1: 5. 5 mm Steel bars with extra soft two components coating to prevent damage to the bicycle's paintwork, Product 1: Colour-matching silicone cover for the lock body with "soft touch" properties, Product 1: Link construction offers compact folding, Product 2: 2018, Product 2: Requires little space, as the lock can be removed at the front. , Product 2: Ideal for small frames

• 
  £101.37

  ABUS Bike Locks

  Granit XPlus 540 U-Lock 160HB300 Anti-Theft, 300 mm + USH540 & Cobra Cable

  Product 1: 13 mm, hardened steel square parabolic shackle, Product 1: ABUS power cell technology offers highest protection against hitting and pulling attacks, Product 1: The shackle, the case as well as supporting elements of the locking mechanism are made of special hardened steel, Product 1: ABUS XPlus cylinder for highest protection against manipulations, e. g. picking, Product 2: Every year millions of bikes are stolen. , Product 2: Police statistics show that only about ten percent of these cases are solved. , Product 2: It doesn't have to be like that, as ABUS covers the whole range of bike security devices with high-quality locks. , Product 2: ABUS offers the right bike lock for every situation

• 
  £434.32

  ABUS Bike Locks

  14KS 6' Maximum Security Square Chain and Sleeve, 9 / 16" Diameter Chain Link

  #14KS 6' Chain and Sleeve

  High Security Chain: This security chain offers optimum security against all types of aggressive attacks Made of hardened steel with a special anti corrosion coating that makes them ideal for outdoor use, Anti Theft Design: This chain features square shaped links, much more effective against attacks with tools The chains also feature a nylon sleeve to prevent scratches and damage to paint work and chrome, Padlocks for Any Application: Discover the variety of our padlocks, from heavy duty Granit padlocks and disc locks to brass, steel and aluminum models, to resettable combination, rekeyable and keyed alike locks, The World's Leading Security Manufacturer: We offer a comprehensive line of home, commercial security and worker safety products including padlocks and hasps, chains and cables, key storage and safety devices, Synonymous with Security: When it comes to protecting lives and valuables, ABUS provides security solutions that help you feel safe and secure. We've been innovating security technology since 1924

• 
  £66.98

  ABUS Bike Locks

  5700 / 100 BU Sh, Lucchetto Pieghevole. Unisex-Adulti, Blu, 100 cm

  #86744 6

  Il modello versatile con livello di sicurezza 7: il lucchetto pieghevole alla moda con barre spesse 5 mm, il cilindro automatico di alta qualità e la pratica modalità di trasporto offrono protezione in caso di rischio di furto basso e medio, Adattabile individualmente: questo modello è disponibile in numerose varianti di colore e può quindi essere utilizzato per ad esempio possono essere adattati visivamente al casco o alla bicicletta, Pieghevole e compatto: i rivetti speciali consentono di piegare la serratura in modo flessibile e di ottenere una dimensione pratica e quindi un trasporto leggero e salvaspazio, Lucchetto antifurto per biciclette: lunghezza 100 cm, peso 1050 g, livello di sicurezza 7, con supporto e 2 chiavi, Sicuro, affidabile e stabile. Questo è il nome ABUS. Che si tratti di protezione domestica, sicurezza degli oggetti o sicurezza mobile: ABUS definisce gli standard

• 
  £61.58

  ABUS Bike Locks

  87786 SmartX RC OEM Frame Locks, Unicolor, one Size

  #87786

  High-quality ABUS product, Model Number: 87786, Material: Aluminium

• 
  £21.50

  ABUS Bike Locks

  4804C, Lucchetto Unisex, Rosso, 75 cm, Red

  #724688

  Item Package Quantity: 1, Model Number: 724688, Package Weight: 360 grams, Colour: red

• 
  £89.99

  ABUS Bike Locks

  Folding Lock Bordo 6000K with Saddlefix Mount and Rain Cover, Bike Lock with XPlus Cylinder for Strong Tamper Protection, Security Level 10, Length 90 cm

  #67865

  Safe and flexible: Foldable bicycle lock with ABUS security level 10, good protection to safeguard against medium theft risk, Solid: 5 mm thick rods and housing made of specially hardened steel The rods are connected by special rivets, Product details: Bordo 6000K/90: length 90 cm (when unfolded), width 64 mm, weight 1207 g, colour black, includes 2 keys, rain cover and bracket, Coating: Folding lock with extra soft and resistant coating on the bars and housing to protect against paintwork damage and provide a good grip

• 
  £39.13

  ABUS Bike Locks

  HB140 - Lucchetto per bicicletta Unisex per adulti, 420 / 150HB140 + USH Ultimate, Black, 14 cm

  #A9816895

  Robusto, compatto e resistente al picking: serratura a U con cilindro di alta qualità per proteggere da manomissioni come ad esempio picking – bloccaggio e sblocco con chiave, Con staffa rotonda da 13 mm in acciaio temprato: alloggiamento, staffa e parti portanti del meccanismo di bloccaggio sono realizzati in acciaio temprato, Design moderno e accattivante, facile da usare grazie al rivestimento del corpo del lucchetto, Lucchetto affidabile per bicicletta e bicicletta elettrica di alta qualità: spessore 13 mm, peso 900 g, altezza 140 mm, larghezza 80 mm, livello di sicurezza ABUS 12, con 2 chiavi e supporto USH, Sicuro, affidabile e stabile. Questo è il nome ABUS. Che si tratti di protezione a casa, di sicurezza degli oggetti o di sicurezza mobile: ABUS definisce gli standard

• 
  £132.23

  ABUS Bike Locks

  32869 Antivol U 58 HB3 100 avec Chaine 12KS 80 cm Loop Homologués SRA Noir, Black

  #32869

  Package Weight: 4. 42 kilograms, Package Dimensions: 5. 0 L x 53. 2 H x 17. 4 W (centimetres), Very Convenient, Easy to use

• 
  £21.14

  ABUS Bike Locks

  Bicycle Lock 5510 K 14245 1 / 180 / 10 Bk S cmu, One Size, Unisex, Fahrradschloss, Red

  #14473-8

  ABUS contributes in a responsible way to the protection of people and valuables, taking care, in many fields of life, of that plus in security, 10 mm thick, high-quality and super flexible spiral cable, Plastic coating to prevent damage to the bicycle’s paintwork, Good protection at low theft risk

• 
  £42.98

  ABUS Bike Locks

  78062 - Lucchetto pieghevole Bordo Lite Mini 6055 / 60 – Extra leggero in acciaio speciale – Livello di sicurezza 7 – 60 cm, Blue

  #78062-2

  Il nostro modello minimalista con livello di sicurezza 7: lucchetto pieghevole compatto e comodo da trasportare con barre in materiali leggeri e leghe di acciaio per una particolare flessibilità e mobilità, Pieghevole e compatto: i rivetti speciali consentono di piegare la serratura in modo flessibile e di ottenere una dimensione pratica e quindi un trasporto leggero e salvaspazio, Piccolo, maneggevole e alla moda: il lucchetto protegge in modo affidabile dai danni alla vernice come ad esempio graffi sulla bicicletta, Lucchetto antifurto per biciclette: lunghezza 60 cm, peso 400 g, livello di sicurezza 7, con 2 chiavi incluse, Sicuro, affidabile e stabile. Questo è il nome ABUS. Che si tratti di protezione domestica, sicurezza degli oggetti o sicurezza mobile: ABUS definisce gli standard

• 
  £65.11

  ABUS Bike Locks

  Goose Lock chain lock - bendable, rattle-free bicycle lock made of hardened steel - 6 mm thick - 110 cm long - with key - security level 7 - blue

  #955471

  SHAPE KEEPER: holds its shape thanks to gooseneck technology,yet flexible at the same time and wraps round the bicycle frame during transport without rattling, SOFT TOUCH: functional, durable, highly flexible coating made of synthetic fibres combined with an underlying foam cover provides a pleasant feel and offers protection against wear, AREA OF APPLICATIONS: for securing bicycles and scooters, suitable for indoor and outdoor use, LOCKING TYPE: two keys included, SECURE: ABUS security level 7 - solid protection for medium theft risk - chain, housing and supporting parts of the locking mechanism are made of specially hardened steel, PRODUCT DETAILS: 6 mm thick and 110 cm long chain with dimensionally stable components and soft coating, chain made of specially hardened steel