Giredhi 8.8 Hex Bolts

2026-08-03

1. Grade 8.8 - Medium-High Strength Fastener Kirasi

1.1 Decoding the 8.8 Designation

Mucherechedzo "8.8" inzvimbo yekirasi yezita inotsanangurwa neISO 898-1, chiyero chepasi rose chinotonga zvimiro zvekabhoni simbi uye alloy simbi yekusimbisa. Iyo-madhiji maviri sisitimu inoisa maviri akakosha mechanical paramita:

● Nhamba yekutanga (8): Inoratidza chikamu chimwe chete chegumi chezita rekugadzirisa simba mu megapascals → 8 × 100 = 800 MPa simba rekuita zvishoma.

● Nhamba yechipiri (.8): Inomiririra chiyero chegoho → 0.8 × 800 = 640 MPa simba shoma regoho.

Giredhi 8.8 mafasteners ndiwo anonyanya kushandiswa-chinangwa chekugadzirisa zvigadziro pasi rese, anovhara hex mabhaudhi, hex cap screws, mabhaudhi engoro, mabhaudhi engoro, uye akarukwa zvizere screws ekuvaka simbi, maassemblies emotokari, uye general muchina.

Mufananidzo 1. Grade 8.8 hex mabhaudhi ane property class marking

1.2 Mechanical Properties

Giredhi 8.8 fasteners inogadzirwa kubva epakati kabhoni simbi uye inodzima uye kupisa (Q&T) kuti iwane inodiwa mekinika kuita. Zvivakwa zvakakosha pa ISO 898-1:

Property	Value	Unit
Minimum Tensile Simba (Rm)	800	MPa
Minimum Yield Strength (ReL)	640	MPa
Minimum Elongation mushure mekutsemuka	≥ 12	%
Core Hardness (HV)	250–310	HV
Yakajairika Q&T Kuoma (HRC)	22–32	HRC
Nominal Bolt Diameter Range	M5 – M39	mm

Tafura 1. Key mechanical properties yeGrade 8.8 fasteners per ISO 898-1

1.3 Zvinokurudzirwa Zvishandiso

Kusarudza mbishi chaiyo ndiyo hwaro hwekuburitsa zvinovimbika zveGrade 8.8 fasteners. Masimbi anotevera, akasanganiswa neQ&T chaiyo, anowana kuita kwakafanana kweGiredhi 8.8:

● 35 # Medium-Carbon Steel - Inokodzera zviduku-diameter fasteners (≤ M16). Inodhura-inoshanda, kuomarara kwakakwana mushure meQ&T.

● 45# Medium-Carbon Steel - Inonyanya kufarirwa sarudzo yeGrade 8.8 hex bolts uye stud bolts. Yakanaka machinability, yakagadzikana michina zvivakwa mushure meQ&T.

● 40Cr Alloy Steel - Inodiwa kune mabhoti makuru-diameter (M20 +). Kuwedzera kweChromium kunonatsiridza kuomarara uye kusimba kwakafanana pamativi ese.

1.4 Giredhi Kuenzanisa

Giredhi	Tensile (MPa)	Goho (MPa)	Zvinokurudzirwa Zvinhu
4.6	400	240	Yakaderera kabhoni simbi, isina-kupisa-yakagadziriswa
4.8	420	340	Yakaderera kabhoni simbi, inotonhora-yakashanda
8.8	800	640	35# / 45# Carbon Steel, 40Cr Alloy Steel; Q&T
10.9	1,040	940	40Cr, 35CrMo, 42CrMo, SCM435; Q&T
12.9	1,220	1,100	42CrMo4 / SCM440, 35CrMoV; Q&T 39–44 HRC

Tafura 2. Common fastener pfuma makirasi uye inokurudzirwa zvinhu

2. Hex Bolts - The Most Versatile Fastener

2.1 Chii Chinonzi Hex Bolt?

Hex bolt (hexagonal head bhaudhi) ishinda ine shinda ine mativi matanhatu musoro, yakagadzirirwa kupinzwa nemumaburi muzvikamu zvakaungana uye inochengetedzwa nenzungu inokwira. Iyo hexagonal geometry inobvumira wrench kana socket kubatikana kubva kumakona akawanda, zvichiita kuti ive yakanyanya kushanda uye yakashandiswa zvakanyanya mhando yebhoti mumaindasitiri ese. Pane misiyano miviri mikuru:

● Hex Bolt (ISO 4014 / DIN 931) - Yakagadzirwa zvishoma: chikamu chisina kuverengwa cheshank chinopa simba reshear uye kurongeka, yakanakira kubatanidzwa kwemaitiro.

● Hex Cap Screw (ISO 4017 / DIN 933) — Yakarukwa zvizere: shinda dzinomhanya kureba kwese, kunokodzera maapplication anoda yakanyanya tambo kubatikana.

Mufananidzo 2. Anatomy ye hex bolt - zvinhu zvakakosha zvekugadzirisa

2.2 Yakajairwa Hex Bolt Mhando & Variants

● Hex Head Bolt / Cap Screw - Musoro wemativi matanhatu; inonyanya kushandiswa, inoshandiswa mukuvaka, michina, motokari.

● Hex Flange Bolt - Yakabatanidzwa washer-yakafanana flange pasi pemusoro; inogovera clamp load, inobvisa washer yakasiyana.

● Heavy Hex Bolt (ASTM A325) - Musoro mukuru wekubatanidza simbi yekugadzira; inotsanangurwa muNorth America zviyero.

● Hex Lag Bolt / Carriage Bolt - Yakasiyana-siyana yakasiyana-siyana yehuni-ku-simbi uye matanda.

2.3 Saizi Yakajairwa & Dimensions

Size	Pitch	Chipanera	Head dia.	Musoro ht.	Shank dia.	Length Range
M6	1.0	10 mm	10.0	4.0	6.0	16–60
M8	1.25	13 mm	13.0	5.3	8.0	20–80
M10	1.5	16 mm	16.0	6.4	10.0	25–100
M12	1.75	18 mm	18.0	7.5	12.0	30–120
M16	2.0	24 mm	24.0	10.0	16.0	40–150
M20	2.5	30 mm	30.0	12.5	20.0	50–200
M24	3.0	36 mm	36.0	15.0	24.0	60–240

Tafura 3. Giredhi 8.8 hex bhaudhi zviyero pa ISO 4014 / ISO 4017

3. Grade 8.8 Hex Bolts — Selection & Application

3.1 Kurapa Kwepamusoro

Kusarudzwa kwekurapa kwepamusoro kunoenderana nemamiriro ekushanda uye corrosion-protection zvinodiwa. Sarudzo dzakajairika dzeGiredhi 8.8 hex mabhoti dzinosanganisira:

● Zinc Plating (Electroplated) - Economical, moderate corrosion resistance; yakajairika sarudzo yemukati uye yakapfava nharaunda.

● Kupisa-Dip Galvanizing - Yakakora zinc coating yekunze uye mugungwa kuratidzwa; zvinoda oversize tapped nzungu.

● Dacromet Coating - Chromium-isina, maitiro ane ushamwari; yepamusoro yemunyu-spray kuramba pasina hydrogen embrittlement njodzi. Yakanakira mota uye zvimiro zvekushandisa.

● Ruspert Coating - Three-layer organic / zinc composite; yakanakisa mamiriro ekunze, anowanzo kutsanangurwa muJapan maindasitiri zviyero.

3.2 Kuisa Nhungamiro

● Shandisa matching Grade 8 nzungu kuti shinda ienderane nesimba.

● Isa yakataurwa yekusimbisa torque papepa remugadziri wedata; kunyanya kuomesa njodzi dzebhaudhi kukundikana.

● Zora shinda pamberi pe torque application - friction coefficient inokanganisa zvakanyanya kuwanikwa pre-load.

● Iva nechokwadi chokuti shinda imwe yakazara yabuda kunze kwechiso chenzungu mushure mekusunga.

● Dzivisa kushandisazve mabhaudhi eGiredhi 8.8 mukubatanidza kwakasimba kwemaitiro mushure mekutanga kurodha yakazara-torque.

3.3 Zviyero & Certification

Giredhi 8.8 hex mabhoti anogadzirwa uye anoedzwa zvinoenderana ne:

● ISO 898-1 - Mechanical properties yezvisungo zvakagadzirwa nekabhoni simbi uye alloy simbi.

● ISO 4014 - Mabhaudhi eHex ane chidimbu chine shinda (dimensions).

● ISO 4017 - Hex cap screws ine shinda yakazara (zviyero).

● Zvitupa zvebvunzo zvakazara (MTC) pa EN 10204 3.1 zviripo pakukumbira.

Quick Reference

Giredhi	Zvinokurudzirwa Zvinhu	Common Product Types	Kupisa Kurapa
8.8	35# / 45# Carbon Steel 40Cr Alloy Steel	Hex Bolt, Hex Cap Screw, Carriage Bolt, Stud Bolt	Kudzima & Kudziya