Added the opportunity to use the grades with different dimensions (such as modified head geometries or special thread lengths) by invoking Supplemental Requirement S2 and adding a "S" to the end of the grade (such as "A325S" or "A490S").
ເພີ່ມໂອກາດໃນການນໍາໃຊ້ຊັ້ນຮຽນທີທີ່ມີຂະຫນາດທີ່ແຕກຕ່າງກັນ (ເຊັ່ນ: ເລຂາຄະນິດຫົວດັດແກ້ຫຼືມີຄວາມຍາວກະທູ້ພິເສດ) ໂດຍ invoking ເສີມ Requirement S2 ແລະເພີ່ມ "S" ໃນຕອນທ້າຍຂອງລະດັບ (ເຊັ່ນ: "A325S" ຫຼື "A490").