JIS B 1176 is not ISO 4762: the standard itself says MOD

So what was modified

The introduction separates what was translated from what was added, and it is worth quoting.

So the dimensional side did not move. Form, dimensions, product specification and the designation examples are a translation with the technical content unchanged. It is MOD because something was added, not because something was altered — terms and definitions, and marking, neither of which the international standards specify.

⚠️ That distinction has a practical edge. If you are only reading dimensions, "same as ISO 4762" will not get you into trouble very often. But the marking requirement exists only on the JIS side. Whether a part marked to ISO 4762 also satisfies the marking requirements of JIS B 1176 does not follow from that sentence.

And the standard ships its own diff

The introduction continues: passages underlined with a solid or dotted side line, together with Annexes JA and JB, are items not present in the corresponding international standards, and the list of changes with explanations is given in Annex JC.

So a reader does not have to guess where the deviations are. The body is marked, the added annexes are named, and Annex JC is in its entirety a comparison table between the JIS and the corresponding international standards.

⚠️⚠️ That table is the contents listing, nothing more. The free preview I could read stops part-way through clause 2, so I have not read a line of any annex. This page therefore gives no limits of size for 5g6g, nothing about property class 12.9, and no detail of the marking requirements. What can be said here is only that JA and JB exist and are informative.

The other thing that gets dropped: it is built on two international standards

"JIS B 1176 = ISO 4762" loses the fine pitch half. The introduction names two:

• ISO 4762 (2004, 4th edition)
• ISO 12474 (2010, 1st edition) — socket head cap screws with metric fine pitch thread

And in the standard's own word, the two were integrated into one document. The scope follows from that: product grade A, coarse thread M1.6 to M64, fine pitch M8×1 to M36×3.

So looking for the fine pitch half in ISO 4762 will not find it. That half came from somewhere else.

The last sentence of clause 1: everything outside dimensions is not in here

That is a product standard declaring its own edge. Thread limits, property class, surface treatment — none of it is inside this document; it is agreed between the parties and picked from other standards.

This site keeps meeting the same shape; where standards stop is the page about it. ⚠️ Put the other way: a drawing that says only "JIS B 1176" has specified no material, no property class and no finish.

The standard's own history

• Established 1 March 1960
• Revised 21 April 2014, gazetted the same day
• The foreword records that JIS B 1176:2006 was revised and replaced by this edition
• Drafted by the Japan Fastener Research Institute (JFRI) and the Japanese Standards Association (JSA)

What travels

• When a description says "identical", go to the note in clause 1. IDT or MOD is written there
• MOD does not necessarily mean different dimensions. Here the introduction says the modification is addition, not alteration
• The practical difference lives in what was added — in this case terms and definitions, and marking
• ⚠️ Do not generalise this to other JIS standards. This page read one of them, and the degree of correspondence is declared standard by standard

⚠️ And this conclusion is declared standard by standard. In the JIS for hex bolts, bolts that are not according to ISO are carried in a normative annex — two families in one standard.

A third one, where the wording differs and the symbol is out of reach

Since the preview route is repeatable, it is worth putting a third standard beside these two. JIS B 1051:2014 is the Japanese counterpart to ISO 898-1, the standard this site cites more than any other — property classes for carbon and alloy steel fasteners.

Its introduction is worded differently from both of the others, and the difference is not decorative.

The first two add requirements. The third adds reference notes. B 1051's introduction also names its basis precisely — ISO 898-1 as published in 2013 in its fifth edition — and says the dotted underlines mark reference matters not present in the corresponding international standard, rather than modifications to it.

References, and how far the reading goes

• JIS B 1176:2014, Hexagon socket head cap screws, read from the preview PDF published by the Japanese Standards Association (the preview path on webdesk.jsa.or.jp). ⚠️ No republishing site was used.
• ⚠️⚠️ How far this page reads: cover, foreword, contents, introduction, clause 1 (scope and its note), and part of clause 2. The preview cuts off inside the list of normative references. Clause 3 (terms and definitions), clause 4 (types), clause 5 (form, dimensions, product specification and designation examples), clause 6 (marking), Annexes A, JA, JB and JC, and the commentary were not read.
• ⚠️ ISO 4762 and ISO 12474 themselves were not read for this page. Everything said about them appears only as what the JIS introduction states.
• ⚠️ No claim is made about any other JIS-to-ISO correspondence. One standard was read.

This is not one of the six steps. It shows up across them, or after assembly. Where the decisions that lead here were made is in specifying a screw, which sets out the order and why doing it out of order is rework.

Common questions

Is JIS B 1176 the same as ISO 4762?

Not identical. The note in clause 1 of JIS B 1176:2014 lists ISO 4762:2004 and ISO 12474:2010 as its corresponding international standards with an overall assessment of MOD, and the same note states that MOD indicates, per ISO/IEC Guide 21-1, that the standard has been modified. The same document uses IDT for JIS B 0143 against ISO 225:2010 and JIS B 0205-2 against ISO 261:1998, so the two symbols are being used precisely.

Does MOD mean the dimensions differ?

Not in this case. The introduction states that the corresponding parts — form and dimensions, product specification, and examples of product designation — were translated and edited without changing the technical content. It is MOD because Japan added requirements the international standards do not specify: terms and definitions, and marking. ⚠️ That is a statement about B 1176 and does not generalise to other JIS standards.

How can I tell where it deviates from the international standard?

The standard marks it. Per the introduction, passages underlined with a solid or dotted side line, plus Annexes JA and JB, are items not present in the corresponding international standards, and the list of changes with explanations is in Annex JC, a comparison table between the JIS and the corresponding international standards. ⚠️ The preview available to me stops part-way through clause 2, so the annex contents were not read.

What is the scope of JIS B 1176?

Product grade A, coarse thread from M1.6 to M64, and fine pitch from M8×1 to M36×3. The fine pitch range is there because the standard was integrated from ISO 12474 as well as ISO 4762 — which is the half that "JIS B 1176 = ISO 4762" drops.

Is writing JIS B 1176 on a drawing enough?

No. The last sentence of clause 1 says that where requirements are needed beyond the dimensions and product specification given in the standard, they are to be selected by agreement between the parties from, for example, JIS B 0205-2, JIS B 0209-2, JIS B 1009, JIS B 1021, JIS B 1051, JIS B 1054-1 and JIS B 1057. Material, property class and surface treatment are not inside this document.