He aha ka 4.8 a me 8.8 ma Bolts Mean?
ʻO nā hōʻailona ma nā bolts, e like me 4.8 a me 8.8, e hōʻike ana i nā māka hana o nā bolts i hoʻohana ʻia i nā pilina o ke kila. Hoʻokaʻawale ʻia kēia mau māka i nā pae he ʻumi me 3.6, 4.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9, a me 12.9. Ma waena o kēia mau mea, ua hana ʻia nā bolts graded 8.8 a i luna mai ke kila haʻahaʻa-carbon alloy a i ʻole ke kila medium-carbon i hoʻomaʻamaʻa ʻia i ka wela (quenching and tempering), i kapa ʻia ʻo nā bolts ikaika kiʻekiʻe. ʻO nā mea ʻē aʻe i ʻike ʻia he mau bolts maʻamau.
ʻO ka mākaʻikaʻi papa hana ʻelua pūʻulu o nā helu e hōʻike ana i ka waiwai ikaika tensile nominal a me ka ratio yield-to-tensile o ka mea bolt. ʻo kahi laʻana:
- ʻO kahi bolt me ka helu hana o 4.8 e hōʻike ana:
- ʻO ka ikaika tensile nominal o ka mea bolt hiki i 400 MPa;
- ʻO ka lākiō hua-a-tensile o ka mea bolt he 0.8;
- No laila, ʻo 400 × 0.8 = 320 MPa ka ikaika hāʻawi inoa o ka mea bolt.
- ʻO kahi bolt ikaika kiʻekiʻe me ka helu hana o 10.9, ma hope o ka mālama wela, hiki ke hoʻokō:
- ʻO ka ikaika tensile nominal o ka mea bolt hiki i 1000 MPa;
- ʻO ka lākiō hua-a-tensile o ka mea bolt he 0.9;
- No laila, ʻo 1000 × 0.9 = 900 MPa ka ikaika hāʻawi inoa o ka mea bolt.
ʻO ka pae hana o nā bolts he maʻamau i ʻike ʻia ma ke ao holoʻokoʻa, e hōʻoia ana i ka hana like ʻana o nā bolts o ka papa like me ka nānā ʻole i kā lākou mea a i ʻole kumu, e ʻae ai i ke koho hoʻolālā e pili ana i ka pae hana.
E pili ana i ka māka ikaika, pono e hoʻomaopopo ʻia ʻaʻole pili nā mea i kapa ʻia he 8.8 a me 10.9 i nā pae koʻikoʻi shear o 8.8 GPa a me 10.9 GPa, akā:
- No ka papa 8.8, ʻo ka ikaika tensile nominal he 800 N/mm², a ʻo ka ikaika hāʻawi nominal he 640 N/mm².
Hōʻike pinepine ʻia ka ikaika o ka bolt e "XY", kahi e like ai ka X100 me ka ikaika tensile o ka bolt, a ʻo X100*(Y/10) e like me ka ikaika hāʻawi o ka bolt (e like me ka convention marking: yield strength/tensile strength = Y/10).
No ka laʻana, no ka papa 4.8 bolt:
- ʻO ka ikaika tensile he 400 MPa;
- ʻO 400 * 8 / 10 = 320 MPa ka ikaika o ka hua.
Hoʻohui ʻia, hōʻailona pinepine ʻia nā bolts stainless steel e like me A4-70 a i ʻole A2-70, he mau ʻano like ʻole e pili ana i nā maʻamau e pili ana i nā mea hoʻopaʻa kila kila.
Mahalo iā ʻoe no ka heluhelu ʻana, inā makemake ʻoe e ʻike hou aku i nā mea a mākou e hāʻawi ai hiki iā ʻoe ke hahai i nā loulou ma lalo nei!