FprEN 6127

Aerospace series - Blind bolt, 100° reduced flush head, high strength

This document specifies the configuration, dimensions, tolerances and mass of a stainless steel blind bolt with 100° reduced flush head for aerospace application.

Luft- und Raumfahrt - Blindbolzen, 100° reduzierter Senkkopf, hochfest

Série aérospatiale - Boulon aveugle, tête fraisée réduite 100°, haute résistance

Le présent document spécifie la configuration, les dimensions, les tolérances et la masse d’un boulon aveugle en acier inoxydable, à tête fraisée réduite 100°, pour les applications aérospatiales.

Aeronavtika - Slepa kovica, 100° zmanjšana ugrezna glava, visoka trdnost

General Information

• Status: Not Published
• Publication Date: 03-Jan-2027
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3/S 2 - Fasteners
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 29-May-2026
• Completion Date: 29-May-2026
• Ref Project: oSIST prEN 6127:2024 - Aerospace series - Blind bolt, 100° reduced flush head, high strength

Overview

FprEN 6127 is a draft European Standard developed by CEN for the aerospace sector, focusing on the specification of stainless steel blind bolts with a 100° reduced flush head and high strength characteristics. This standard defines the configuration, dimensions, tolerances, and mass for these specific fasteners, ensuring reliability and consistency in aerospace applications. The document is intended to harmonize product characteristics across the industry, improving interoperability and safety.

Key Topics

• Configuration: Defines the geometry and specific features of the 100° reduced flush head blind bolt, including options for shifting anvil/drive washer and serrated pin geometry.
• Dimensions and Tolerances: Sets precise measurements and permissible variations to ensure fit and function in demanding aerospace applications.
• Material and Finish: Specifies corrosion-resistant materials (A-286 CRES, 316 CRES, Inconel 600) and processes such as passivation and resin-based coatings for enhanced durability and performance.
• Grip Range and Mass: Details the available lengths and mass per 1,000 pieces, supporting efficient selection for varied installation requirements.
• Designation and Marking: Provides a standardized approach to part numbering and mandatory head marking according to EN 2424, aiding product identification and traceability.
• Technical Specification Linkage: Ties strength, preload, and spindle retention closely to NASM8975, except where otherwise detailed in the standard.

Applications

The FprEN 6127 blind bolt is engineered for critical aerospace assemblies where reliable fastening and minimal protrusion are essential. Its applications include:

• Aircraft Structures: Used in joining structural components such as fuselage skins, frames, and panels where only one side is accessible (blind installation).
• Interiors and Systems: Applicable in the attachment of avionics racks, seating structures, or other subassemblies requiring high strength and flush finishes.
• Retrofitting and Repairs: Well-suited for maintenance scenarios, especially where original access is limited or components have to be replaced without major disassembly.
• Lightweight Construction: The use of stainless steel and specific mass requirements supports modern demands for reduced weight without compromising strength.
• Corrosive Environments: The specified passivation and coatings are suitable for exterior or moisture-prone areas where corrosion resistance is critical to longevity and safety.

Related Standards

To ensure comprehensive compliance and compatibility, reference is made to a set of related European and international aerospace standards, including:

• EN 2424: Aerospace series - Marking of aerospace products
• EN 4473: Aerospace series - Aluminium pigmented coatings for fasteners - Technical specification
• NASM8975: Fastener, Blind, High Strength, Installation Formed - General Specification
• SAE AMS2700: Passivation of corrosion resistant steels
• SAE AMS5687 / AMS5690 / AMS5737: Specifications for corrosion- and heat-resistant alloys used in aerospace fasteners
• MIL-PRF-46010, SAE AS5272, DOD-L-85645, SAE AS87132: Specifications for lubricants and coatings used on aerospace fasteners

Practical Value

The implementation of FprEN 6127 ensures that aerospace manufacturers, suppliers, and maintenance providers utilize standardized, high-strength blind bolts, contributing to:

• Enhanced Interchangeability: Standardized dimensions allow for global sourcing and simplified logistics.
• Consistent Quality: Defined tolerances and materials ensure each blind bolt meets the rigor of aerospace performance requirements.
• Improved Traceability: Standardized marking and designation facilitate maintenance, safety audits, and regulatory compliance.
• Reduced Risk: By referencing up-to-date materials and coatings, the standard helps mitigate against corrosion and mechanical failure.

By applying this standard, the aerospace industry benefits from greater efficiency, reliability, and safety in the assembly and repair of critical aircraft structures.

Standards Content (Sample)

SLOVENSKI STANDARD
01-oktober-2024
Aeronavtika - Slepa kovica, 100° zmanjšana ugrezna glava, visoka trdnost
Aerospace series - Blind bolt, 100° reduced flush head, high strength
Luft- und Raumfahrt - Blindbolzen, 100° reduzierter Senkkopf, hochfest
Série aérospatiale - Boulon aveugle, tête fraisée réduite 100°, haute résistance
Ta slovenski standard je istoveten z: prEN 6127
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
prEN 6127
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2024
ICS 49.030.20
English Version
Aerospace series - Blind bolt, 100° reduced flush head,
high strength
Série aérospatiale - Boulon aveugle, tête fraisée réduite Luft- und Raumfahrt - Blindbolzen, 100° reduzierter
100°, haute résistance Senkkopf, 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 6127:2024 E
worldwide for CEN national Members.

prEN 6127:2024 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Requirements . 5
4.1 Configuration, dimensions and tolerances . 5
4.2 Grip range and mass . 5
4.3 Material, finish and lubrication . 5
4.4 First oversize . 5
5 Designation . 17
6 Marking . 17
7 Technical specification . 17
prEN 6127:2024 (E)
European foreword
This document (prEN 6127:2024) 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 ASD-STAN prEN 6127:2006.
This document includes the following significant technical changes with respect to ASD-
STAN prEN 6127:2006:
a) Figure 1 and Figure 2 updated (dimensions Q and X 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.
prEN 6127:2024 (E)
1 Scope
This document specifies the configuration, dimensions, tolerances and mass of a stainless steel blind bolt
with 100° reduced 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, Aerospace series — Marking of aerospace products
EN 4473, Aerospace series — Aluminium pigmented coatings for fasteners — Technical specification
DOD-L-85645, Lubricant, Dry Film, Molecular Bonded
MIL-PRF-46010, Lubricant, Solid Film, Heat Cured, Corrosion Inhibiting NATO Code – S-1738
NASM8975, Fastener, Blind, High Strength, Installation Formed, Cres, Heat Resistant Steel and Titanium,
General Specification for
SAE AMS2700, Passivation of Corrosion Resistant Steels
SAE AMS5687, Nickel Alloy, Corrosion- and Heat-Resistant, Wire 74Ni-15.5Cr-8.0Fe Annealed
SAE AMS5690, Steel, Corrosion and Heat Resistant, Wire 17Cr-12Ni-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
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/

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/.
prEN 6127:2024 (E)
4 Requirements
4.1 Configuration, dimensions and tolerances
The configuration, dimensions, tolerances, static strength, tensile preload and spindle retention shall
conform to Figure 1, Figure 2 and 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 shall be according to Table 7, Table 8 and Table 9.

a) Bolt configuration
prEN 6127:2024 (E)
b) Serrated pin geometry
Key
1 marking see Clause 6 5 grip
2 serrated pin 6 sleeve
3 locking collar 7 shifting anvil
4 crown height (C) 8 drive washer
a
Diameter of pin head shall not exceed “⌀D” max.
b
Fasteners are supplied with shifting anvil/drive washer of manufacturer’s option. The shifting anvil/drive
washer is not part of the installed fastener.
c
optional configuration
Figure 1 — Configuration and dimensions

Key
1 grip
a
Blind side head may be installed on 7° max. slope.
Figure 2 — Typical installation
prEN 6127:2024 (E)
Table 1 — Dimensions and tolerances
Dimensions in mm (inch)
Diameter code
05 06 08
Theor. 7,37 9,07 12,19
⌀A
(0,290) (0,357) (0,480)
Ref.
1,32 1,65 2,31
B Ref.
(0,052) (0,065) (0,091)
0,25 0,25 0,31
C max.
(0,010) (0,010) (0,012)
0,584 0,762 1,016
0,508 0,686 0,914
H Gage HT
(0,023 0) (0,030 0) (0,040 0)
(0,020 0) (0,027 0) (0,036 0)
5,946 7,216 9,792
5,941 7,211 9,787
⌀W Gage Dia.
(0,234 1) (0,284 1) (0,385 5)
(0,233 9) (0,283 9) (0,385 3)
±0,03 4,14 5,03 6,58
⌀D
(±0,001) (0,163) (0,198) (0,259)
±0,13 9,53 9,53 9,53
a
⌀J
(±0,005) (0,375) (0,375) (0,375)
±1,52 3,56 4,06 4,83
N
(±0,060) (0,140) (0,160) (0,190)
3,05 3,81 4,83
⌀D max.
(0,120) (0,150) (0,190)
2,16 2,79 3,66
⌀D max.
(0,085) (0,110) (0,144)
7,62 8,13 9,40
b
P max.
(0,300) (0,320) (0,370)
5,66 6,86 9,02
⌀P min.
(0,223) (0,270) (0,355)
0,25 0,38 0,51
R max.
(0,010) (0,015) (0,020)
5,89 7,42 9,17
S max.
(0,232) (0,292) (0,361)
±0,76 20,32 21,08 24,77
J
(±0,030) (0,800) (0,830) (0,975)
prEN 6127:2024 (E)
Diameter code
05 06 08
Number of
serrations
J 18 19 20
min.
±0,76 1,52 1,78 2,29
X
(±0,030) (0,060) (0,070) (0,090)
0,13 0,13 0,13
E min.
(0,005) (0,005) (0,005)
0,33 0,33 0,33
C Ref.
(0,013) (0,013) (0,013)
±0,05 0,81 0,81 0,81
C
(±0,002) (0,032) (0,032) (0,032)
F ±5° 45° 45° 45°
G ±5° 30° 30° 30°
a
Diameter code 05 is also available with reduced diameter shifting anvil/drive washer [7,93 mm ± 0,13 mm
(0,312 inch ± 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
Dimensions in kN (lbf)
Diameter code Single shear Tensile Tensile preload Spindle retention
strength strength
min. min. min. min.
8,807 4,671 0,467 2,335
(1 980) (1 050) (105) (525)
13,011 6,672 0,667 3,336
(2 925) (1 500) (150) (750)
22,242 11,565 1,157 5,783
(5 000) (2 600) (260) (1 300)
prEN 6127:2024 (E)
Table 3 — Grip range
Dimensions in mm (inch)
Grip Under lap Grip range Over Diameter code
length lap
05 06 08
code
min. min. min. max. max. L K L K L K
only 06 dia.   05 dia. Ref. max. Ref. max. Ref. max.
05 dia. to 08 to 08
dia. 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 14,83 12,17 16,38
(0,146) (0,140) (0,156) (0,220) (0,236) (0,398) (0,539) (0,417) (0,584) (0,479) (0,645)
5,31 5,16 5,56 7,16 7,57 11,68 15,29 12,19 16,43 13,74 17,98
(0,209) (0,203) (0,219) (0,282
...