prEN 6122

Aerospace series - Blind bolt, 130° flush head, high strength

This document specifies the configuration, dimensions, tolerances and mass of a stainless steel and titanium blind bolt with 130° flush head for aerospace application.

Luft- und Raumfahrt - Blindbolzen, 130° Senkkopf, hochfest

Série aérospatiale - Boulon aveugle, Tête fraisée 130°, haute résistance

Le présent document spécifie la configuration, les dimensions, les tolérances et la masse d’un boulon aveugle en acier inoxydable et titane, à tête fraisée 130°, pour les applications aérospatiales.

Aeronavtika - Slepa kovica, 130° ugrezna glava, visoka trdnost

General Information

• Status: Not Published
• Publication Date: 09-Feb-2026
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3/S 2 - Fasteners
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 07-Nov-2024
• Completion Date: 07-Nov-2024
• Ref Project: oSIST prEN 6122:2024 - Aerospace series - Blind bolt, 130° flush head, high strength

Overview

The draft European Standard prEN 6122:2024 focuses on high-strength blind bolts designed for aerospace applications. Specifically, it defines the configuration, dimensions, tolerances, and mass of stainless steel and titanium blind bolts featuring a 130° flush head. Developed by the CEN Technical Committee ASD-STAN, this standard aims to ensure uniformity and optimal performance of blind bolts used in critical aerospace structures.

As a replacement for the previous 2005 version, this updated standard incorporates technical improvements including revised figures and tables, removal of certain dimensions, updated normative references, and the introduction of an oversize category “X.” This rigorous standard supports aerospace manufacturers by establishing consistent mechanical properties and installation criteria for critical fasteners.

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Key Topics

• Blind Bolt Design and Dimensions

  • Specifies bolt configuration, including a 130° flush countersunk head.
  • Contains detailed dimensions and tolerances for various diameter codes (05 to 10).
  • Describes serrated pin geometry and locking collar design for secure fastening.

• Materials

  • Stainless steel (CRES) and titanium options commonly used in aerospace.
  • Requirements for material finish and lubrication based on referenced aerospace and military specifications (e.g., ASTM B348, SAE AMS2700).

• Mechanical Requirements

  • Static strength, including single shear strength and tensile strength, with specific minimum values for each diameter and material.
  • Tensile preload and spindle retention criteria for reliable, durable fastening.

• Grip Range and Mass

  • Defines grip length ranges and underlap/overlap limits for proper assembly.
  • Provides mass values per 1,000 pieces to assist in weight management in aerospace designs.

• Marking and Designation

  • Recommends standardized marking guidelines aligned with EN 2424 for traceability and quality assurance.
  • Clear designation system for easy identification of bolt specifications.

• Optional Features

  • Oversize “X” category for certain applications.
  • Manufacturer options for drive washers and shifting anvils, ensuring compatibility and ease of installation.

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Applications

This aerospace-specific blind bolt standard is critical for manufacturers and engineers involved in the assembly and maintenance of aircraft and aerospace components, where reliable fastening under extreme conditions is mandatory. Typical applications include:

• Structural assembly where access is limited to one side (blind fastening).
• High-strength joints requiring flush head fasteners for aerodynamic surface finishes.
• Use in aluminum, titanium, and composite airframe constructions.
• Critical mounting points in engine and landing gear assemblies that demand precise preload and strength.
• Aerospace maintenance and repair operations requiring replacement with standardized fasteners.

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Related Standards

The implementation and compliance of prEN 6122:2024 depend on a variety of complementary standards:

• EN 2424:2008 - Aerospace product marking for traceability.
• EN 4473 - Technical specifications for aluminum pigmented coatings used in fasteners.
• ISO 8080 - Anodic treatment of titanium and alloys for corrosion resistance.
• ASTM B348 - Titanium and titanium alloy bars specification.
• SAE AMS2700 - Passivation processes for corrosion-resistant steels.
• NASM 8975 - General specification for high-strength blind fasteners.
• Various SAE and MIL lubricant specifications - Ensure solid film lubricants and corrosion-inhibiting coatings meet aerospace standards.

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Keywords: aerospace blind bolt, 130° flush head, high strength fastener, stainless steel blind bolt, titanium blind bolt, aerospace fasteners, blind fastening, CEN aerospace standards, prEN 6122, aerospace bolt dimensions, high-strength aerospace fasteners.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2024
Aeronavtika - Slepa kovica, 130° ugrezna glava, visoka trdnost
Aerospace series - Blind bolt, 130° flush head, high strength
Luft- und Raumfahrt - Blindbolzen, 130° Senkkopf, hochfest
Série aérospatiale - Boulon aveugle, Tête fraisée 130°, haute résistance
Ta slovenski standard je istoveten z: prEN 6122
ICS:
49.030.20 Sorniki, vijaki, stebelni vijaki Bolts, screws, studs
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2024
ICS 49.030.20 Will supersede
English Version
Aerospace series - Blind bolt, 130° flush head, high
strength
Série aérospatiale - Boulon aveugle, Tête fraisée 130°, Luft- und Raumfahrt - Blindbolzen, 130° Senkkopf,
haute résistance hochfest
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 6122:2024 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Requirements . 5
4.1 Configuration, dimensions, tolerances, static strength, preload and spindle retention . 5
4.2 Grip range and mass . 5
4.3 Material, finish and lubrication . 5
4.4 First oversize . 5
5 Designation . 22
6 Marking . 22
7 Technical specification . 22

European foreword
This document (prEN 6122:2024) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document is currently submitted to the CEN Enquiry.
This document will supersede prEN 6122:2005 .
This document includes the following significant technical changes with respect to prEN 6122:2005:
a) Figure 1 and Figure 2 updated (dimension Q removed);
b) dimension Q removed in Table 1 accordingly;
c) Table 1 and Table 3: Single values corrected and hole limits removed;
d) Table 5 and Table 6 updated according updated normative references and preferred options;
e) oversize “X” added in document.

Published by ASD-STAN, available at https://www.asd-stan.org.
1 Scope
This document specifies the configuration, dimensions, tolerances and mass of a stainless steel and
titanium blind bolt with 130° flush head for aerospace application.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 2424:2008, Aerospace series — Marking of aerospace products
EN 4473, Aerospace series — Aluminium pigmented coatings for fasteners — Technical specification
ISO 8080, Aerospace — Anodic treatment of titanium and titanium alloys — Sulfuric acid process
ASTM B348, Standard Specification for Titanium and Titanium Alloy Bars and Billets
DOD-L-85645, Lubricant, Dry Film, Molecular Bonded
MIL-PRF-46010, Lubricant, Solid Film, Heat cured, Corrosion Inhibiting NATO Code – S-1738
NASM 8975, Fastener, Blind, High Strength, Installation Formed, Cres, Heat Resistant Steel and Titanium,
General Specification for
SAE AMS2700, Passivation of Corrosion Resistant Steels
SAE AMS4957, Titanium Alloy, Round Bar and Wire, 3Al-8V-6Cr-4Mo-4Zr, Consumable Electrode Melted
Solution Heat Treated and Cold Drawn
SAE AMS5687, Nickel Alloy, Corrosion- and Heat-Resistant, Wire 74Ni-15,5Cr-8,0Fe Annealed
SAE AMS5690, Steel, Corrosion and Heat Resistant, Wire, 17Cr-12N-2.5Mo (316), Solution Heat Treated
SAE AMS5737, Steel, Corrosion and Heat Resistant, Bars, Wire, Forgings, Mechanical Tubing, and Stock
for Forging and Heading 15Cr-25,5Ni-1,2Mo-2,1Ti-0,006B-0,30V (A286) Consumable Electrode Remelted,
1650 °F (899 °C) Solution and Precipitation Heat Treated
SAE AS5272, Lubricant, Solid Film; Heat Cured, Corrosion Inhibiting Procurement Specification
SAE AS87132, Lubricant, Cetyl Alcohol, 1-Hexadecanol, Application to Fasteners

Published by American Society for Testing and Materials (ASTM International), available at:
https://www.astm.org/.
Published by Department of Defense (DoD), available at: https://assist.dla.mil/.
Published by Aerospace Industries Association (AIA), available at: https://www.aia-aerospace.org/.
Published by Society of Automotive Engineers (SAE), available at: https://www.sae.org/.
3 Terms and definitions
No terms and definitions are listed in this document.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp/
— IEC Electropedia: available at https://www.electropedia.org/
4 Requirements
4.1 Configuration, dimensions, tolerances, static strength, preload and spindle retention
The configuration, dimensions, tolerances, static strength, tensile preload and spindle retention shall
conform to Figure 1, Figure 2, Table 1 and Table 2.
4.2 Grip range and mass
Grip range and mass shall be according to Table 3 and Table 4.
4.3 Material, finish and lubrication
Material, finish and lubrication shall be according to Table 5 and Table 6.
4.4 First oversize
First oversize “X” shall be in CRES and according to Table 7, Table 8, Table 9 and Table 10.
a) Bolt configuration
b) Serrated pin geometry
Key
1 marking, see Clause 6
2 serrated pin
3 locking collar
4 0,005 Ref. crown height
5 grip
6 sleeve
7 shifting anvil
8 drive washer
Diameter of pin head shall not exceed “⌀D” max
Fasteners are supplied with shifting anvil/drive washer of manufacturer’s option. The shifting
anvil/drive washer is not part of the installed fastener.
Optional configuration.
Figure 1 — Configuration, dimensions

Key
1 grip
Blind side head may be installed on 7° max. slope.
Figure 2 — Typical installation
Table 1 — Dimensions and tolerances, CRES and titanium
Dimensions in mm (inch)
Diameter code
05 06 07 08 09 10
Theor.
8,43 9,80 10,57 12,88 13,66 16,13
⌀A
(0,332) (0,386) (0,416) (0,507) (0,538) (0,635)
Ref.
⌀A2 min. 7,52 8,81 9,47 11,76 12,55 14,66
(0,296) (0,347) (0,373) (0,463) (0,494) (0,577)
0,99 1,09 1,09 1,45 1,45 1,91
B Ref.
(0,039) (0,043) (0,043) (0,057) (0,057) (0,075)
0,478 0,488 0,627 0,602 0,754 0,704
0,376 0,386 0,561 0,500 0,696 0,638
H Gage HT
(0,018 8) (0,019 2) (0,024 7) (0,023 7) (0,029 7) (0,027 7)
(0,014 8) (0,015 2) (0,022 1) (0,019 7) (0,027 4) (0,025 1)
7,193 8,311 8,420 10,973
10,973 13,688
7,188 8,306 8,415 10,968 10,968 13,678
⌀W Gage dia.
(0,283 2) (0,327 2) (0,331 5) (0,432 0) (0,432 0) (0,538 9)
(0,283 0) (0,327 0) (0,331 3) (0,431 8) (0,431 8) (0,538 5)
±0,03 4,14 5,03 5,74 6,58 7,31 7,88
⌀D
(±0,001) (0,163) (0,198) (0,226) (0,259) (0,288) (0,310)
±0,13 9,53 9,53 9,53 9,53 9,53 11,13
a
⌀J
(±0,005) (0,375) (0,375) (0,375) (0,375) (0,375) (0,438)
±1,52 3,56 4,06 4,45 4,83 5,33 6,09
N
(±0,060) (0,140) (0,160) (0,175) (0,190) (0,210) (0,240)
3,05 3,81 4,14 4,83 5,23 5,61
⌀D max.
(0,120) (0,150) (0,163) (0,190) (0,206) (0,221)
2,16 2,79 3,17 3,66 4,06 4,82
⌀D max.
(0,085) (0,110) (0,125) (0,144) (0,160) (0,190)
7,62 8,13 8,89 9,40 10,92 12,70
b
P max.
(0,300) (0,320) (0,350) (0,370) (0,430) (0,475)
5,66 6,86 7,82 9,02 9,96 10,41
⌀P min.
(0,223) (0,270) (0,308) (0,355) (0,392) (0,410)
0,64 0,64 0,76 0,76 0,76 1,01
R max
(0,025) (0,025) (0,030) (0,030) (0,030) (0,040)
5,89 7,42 8,17 9,17 10,16 11,22
S max.
(0,232) (0,292) (0,322) (0,361) (0,400) (0,442)
±0,76 20,32 21,08 22,60 24,77 26,67 26,67
J
(±0,030) (0,800) (0,830) (0,890) (0,975) (10,050) (10,050)
Diameter code
05 06 07 08 09 10
Number
of
J 18 19 20 20 20 20
serrations
min.
±0,76 1,52 1,78 2,28 2,29 2,29 2,29
X
(±0,030) (0,060) (0,070) (0,090) (0,090) (0,090) (0,090)
0,13 0,13 0,13 0,13 0,13 0,13
E min.
(0,005) (0,005) (0,005) (0,005) (0,005) (0,005)
0,33 0,33 0,33 0,33 0,33 0,33
C Ref.
(0,013) (0,013) (0,013) (0,013) (0,013) (0,013)
±0,05 0,81 0,81 0,79 0,81 0,79 0,79
C
(±0,002) (0,032) (0,032) (0,031) (0,032) (0,031) (0,031)
F ±5° 45° 45° 45° 45° 45° 45°
G ±5° 30° 30° 30° 30° 30° 30°
a
Diameter code 05 is also available with reduced diameter shifting anvil/drive washer
[(7,93 ± 0,13) mm/(0,312 ± 0,005) inch]. See part number examples.
b
In the length of P, ⌀D may be 0,05 mm (0,002 inch) undersize.
Table 2 — Static strength (installed), tensile preload, spindle retention
Strength in kN (lbf)
Diameter Single shear Tensile strength Tensile preload Spindle retention
code strength
min. min. min. min.
CRES Ti CRES Ti CRES Ti CRES Ti
8,807 8,807 4,671 3,603 0,467 0,544 2,335 1,824
(1 980) (1 980) (1 050) (810) (105) (121) (525) (410)
13,011 13,011 6,672 5,605 0,667 0,841 3,336 2,804
(2 925) (2 925) (1 500) (1 260) (150) (189) (750) (630)
17,036 8,851 0,885 4,337
07 — — — —
(3 830) (1 990) (199) (975)
22,241 22,241 11,565 8,407 1,157 1,263 5,783 4,204
(5 000) (5 000) (2 600) (1 890) (260) (284) (1300) (945)
27,623 14,345 1,436 7,117
09 — — — —
(6 210) (3 225) (323) (1 600)
32,027 16,680 1,668 8,340
10 — — — —
(7 200) (3 750) (375) (1 875)
Table 3 — Grip range
Dimensions in mm (inch)
Diameter code
05 06 07 08 09 10
Grip Underlap Grip Range Overlap L K L K L K L K L K L K
length
min. min. min. max. max. Ref. max. Ref. max. Ref. max. Ref. max. Ref. max. Ref. max.
code
only 05 06 dia. to  05 dia. to
dia. 10 dia. 10 dia.
a
2,39 3,99 4,39 8,53 12,09 9,02 13,23
02 — — — — — — — — — —
(0,094) (0,157) (0,173) (0,336) (0,476) (0,355) (0,521)
b
3,71 3,56 3,96 5,59 5,99 10,11 13,69 10,59 14,81 12,29 16,38 12,17 16,38 13,67 18,39
03 — —
(0,146) (0,140) (0,156) (0,220) (0,236) (0,398) (0,539) (0,417) (0,583) (0,484) (0,645) (0,479) (0,645) (0,538) (0,724)
5,31 5,16 5,56 7,16 7,57 11,68 15,29 12,19 16,41 13,49 17,58 13,74 17,96 14,86 19,58 15,44 20,45
(0,585)
(0,209) (0,203) (0,219) (0,282) (0,298) (0,460) (0,602) (0,480) (0,646) (0,531) (0,692) (0,541) (0,707) (0,771) (0,608) (0,805)
6,88 6,73 7,14 8,76 9,17 13,28 16,87 13,77 17,98 15,06 19,15 15,34 19,56 16,43 21,16 17,04 22,05
(0,271) (0,265) (0,281) (0,345) (0,361) (0,523) (0,664) (0,542) (0,708) (0,593) (0,754) (0,604) (0,770) (0,647) (0,833) (0,671) (0,868)
8,48 8,33 8,74 10,34 10,74 14,86 18,47 15,37 19,58 16,66 20,75 16,92 21,13 18,03 22,76 18,62 23,62
(0,334) (0,328) (0,344) (0,407) (0,423) (0,585) (0,727) (0,605) (0,771) (0,656) (0,817) (0,666) (0,832) (0,710) (0,896) (0,733) (0,930)
10,06 9,91 10,31 11,94 12,34 16,46 20,04 16,94 21,16 18,24 22,33 18,52 22,73 19,61 24,33 20,22 25,22
(0,396) (0,390) (0,406) (0,470) (0,486) (0,648) (0,789) (0,667) (0,833) (0,781) (0,879) (0,729) (0,895) (0,772) (0,958) (0,796) (0,993)
11,66 11,51 11,91 13,51 13,92 18,03 21,64 18,54 22,76 19,84 23,93 20,09 24,31 21,21 25,93 21,79 26,80
(0,459) (0,453) (0,469) (0,532) (0,548) (0,710) (0,852) (0,730) (0,896) (0,781) (0,942) (0,791) (0,957) (0,835) (1,021) (0,858) (1,055)
13,23 13,08 13,49 15,11 15,52 19,63 23,22 20,12 24,33 21,41 25,50 21,69 25,91 22,78 27,51 23,39 28,40
(0,521) (0,515) (0,531) (0,595) (0,611) (0,773) (0,914) (0,792) (0,958) (0,843) (1,004) (0,854) (1,020) (0,897) (1,083) (0,921) (1,118)
14,83 14,68 15,09 16,69 17,09 21,21 24,82 21,72 25,93 23,01 27,10 23,27 27,48 24,38 29,11 24,97 29,97
(0,584) (0,578) (0,594) (0,657) (0,673) (0,835) (0,977) (0,855) (1,021) (0,906) (1,067) (0,916) (1,082) (0,960) (1,146) (0,983) (1,180)
16,41 16,26 16,66 18,29 18,69 22,81 26,39 23,29 27,51 24,59 28,68 24,87 29,08 25,96 30,68 26,57 31,57
(1,022)
(0,646) (0,640) (0,656) (0,720) (0,736) (0,898) (1,039) (0,917) (1,083) (0,968) (1,129) (0,979) (1,145) (1,208) (1,046) (1,243)
Diameter code
05 06 07 08 09 10
Grip Underlap Grip Range Overlap L K L K L K L K L K L K
length
min. min. min. max. max. Ref. max. Ref. max. Ref. max. Ref. max. Ref. max. Ref. max.
code
only 05 06 dia. to  05 dia. to
dia. 10 dia. 10 dia.
18,01 17,86 18,26 19,86 20,27 24,38 27,99 24,89 29,11 26,19 30,28 26,44 30,658 27,56 32,28 28,14 33,15
(0,709) (0,703) (0,719) (0,782) (0,798) (0,960) (1,102) (0,980) (1,146) (1,031) (1,192) (1,041) (1,207) (1,085) (1,271) (1,108) (1,305)
19,58 19,43 19,84 21,46 21,87 25,98 29,57 26,47 30,68 27,76 31,85 28,04 32,26 29,13 33,86 29,74 34,75
(0,771) (0,765) (0,781) (0,845) (0,861) (1,023) (1,164) (1,042) (1,208) (1,093) (1,254) (1,104) (1,270) (1,147) (1,333) (1,171) (1,368)
21,18 21,03 21,44 23,04 23,44 27,56 31,17 28,07 32,28 29,36 33,45 29,62 33,83 30,73 35,46 31,32 36,32
(0,834) (0,828) (0,844) (0,907) (0,923) (1,085) (1,227) (1,105) (1,271) (1,156) (1,317) (1,166) (1,332) (1,210) (1,396) (1,233) (1,430)
22,76 22,61 23,01 24,64 25,04 29,16 32,74 29,64 33,86 30,94 35,03 31,22 35,43 32,31 37,03 32,92 37,92
(0,896) (0,890) (0,906) (0,970) (0,986) (1,148) (1,289) (1,167) (1,333) (1,218) (1,379) (1,229) (1,39
...