kSIST FprEN 6127:2026

• Abstract:

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

• Status: Not Published
• Public Enquiry End Date: 15-Oct-2024
• ICS: 49.030.20 - Bolts, screws, studs
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 06-Aug-2026
• Due Date: 24-Sep-2026
• Completion Date: 07-Aug-2026
• Ref Project: FprEN 6127 - Aerospace series - Blind bolt, 100° reduced flush head, high strength

Overview

kSIST FprEN 6127:2026 is a European aerospace standard developed by SIST, specifying the requirements for stainless steel blind bolts featuring a 100° reduced flush head design and high strength. This standard is intended for aerospace applications where reliable, flush-mounted, high-strength fastening is critical. It defines the configuration, dimensions, tolerances, and mass for these specialized fasteners, ensuring uniformity and compatibility in the aerospace industry.

Key Topics

• Configuration and Dimensions: The standard provides comprehensive details on the bolt’s configuration, including head angle, reduced flush design, and fitment requirements. Specific grip ranges, lengths, and diameters are precisely defined to match various aeronautical construction needs.
• Material Specifications: Only specific corrosion- and heat-resistant stainless steels (such as A-286 CRES, 316 CRES, and Inconel 600, among others) are permitted, following established aerospace material specifications and passivation protocols for durability and performance.
• Finishes and Lubrication: Surface finishes and lubrication requirements are dictated according to aerospace coating and passivation standards. Options include passivation per SAE AMS2700 and resin-based aluminum pigment coatings per EN 4473, ensuring corrosion resistance and reliable fastener performance.
• Tolerances and Mass: Detailed tolerances and mass per unit are established to assist with design calculations, assembly, and weight management in aerospace structures.
• Marking and Identification: Standardized marking according to EN 2424 ensures traceability and consistent identification of bolt type, grip length, and manufacturer, supporting maintenance and quality assurance.

Applications

Blind bolts with a 100° reduced flush head, as specified in kSIST FprEN 6127:2026, are designed to meet the rigorous requirements of the aerospace industry, where they are typically used in:

• Aircraft Structures: Providing high-strength, flush fastener solutions where access is limited to one side of the assembly, such as in fuselage panels, flooring, and wing skins.
• Aerospace Component Assembly: Used in environments requiring corrosion resistance, vibration resistance, and minimal aerodynamic disturbance.
• Retrofit and Repair: First oversize options are addressed to enable replacement or repair of fastener holes that have enlarged from service wear or earlier removals.

These bolts are ideal for scenarios demanding a combination of high structural strength, low-profile head configuration, and rapid installation without access to both sides of the assembly-a frequent challenge in aeronautical fabrication and maintenance.

Related Standards

Several related standards are referenced or influence requirements in kSIST FprEN 6127:2026:

• EN 2424 - Aerospace series, marking of aerospace products
• EN 4473 - Technical specification for aluminium pigmented coatings for fasteners
• NASM8975 - Specification for high-strength blind fasteners (Cres, heat-resistant, titanium)
• SAE AMS2700 - Passivation of corrosion resistant steels
• MIL-PRF-46010, SAE AS5272, AS87132, DOD-L-85645 - Lubricant and coating specifications
• SAE AMS5687, AMS5690, AMS5737 - Material requirements for nickel and stainless steel alloys

The standard ensures alignment with widely recognized aerospace supplier and material requirements, facilitating international compliance and interchangeability.

---

By conforming to kSIST FprEN 6127:2026 when specifying or procuring aerospace blind bolts with flush heads and high strength, organizations and engineers ensure compatibility, safety, and performance in demanding aerospace environments. Adoption of this standard is crucial for quality assurance, regulatory compliance, and efficient maintenance processes in global aviation.

SLOVENSKI STANDARD
oSIST prEN 6127:2024
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
oSIST prEN 6127:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 6127:2024
oSIST prEN 6127:2024
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.

oSIST prEN 6127:2024
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
oSIST prEN 6127:2024
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.
oSIST prEN 6127:2024
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/.
oSIST prEN 6127:2024
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
oSIST prEN 6127:2024
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
oSIST prEN 6127:2024
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)
oSIST prEN 6127:2024
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)
oSIST prEN 6127:2024
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
...