Bootstrap 4 border utilities

Suggests to add a bootstrap extension.

/* _border-width-customs.scss */
$border-width-custom-1: 1px !default;
$border-width-custom-2: 2px !default;
$border-width-custom-3: 3px !default;
$border-width-custom-4: 4px !default;
$border-width-custom-5: 5px !default;
$border-width-custom-6: 6px !default;
$border-width-custom-7: 7px !default;
$border-width-custom-8: 8px !default;

$border-width-customs: ("1": $border-width-custom-1, "2": $border-width-custom-2, "3": $border-width-custom-3, "4": $border-width-custom-4, "5": $border-width-custom-5, "6": $border-width-custom-6, "7": $border-width-custom-7, "8": $border-width-custom-8);

@each $name, $size in $border-width-customs {
    @each $var in '', 'top-', 'right-', 'bottom-', 'left-' {
        .border-#{$var}#{$name} { border-#{$var}width: $size !important; border-#{$var}style: solid; border-#{$var}color: $border-color;}
    }
}

No, there are no classes in Bootstrap 4 for border width or style.

You can simply add something like:

.border-3 {
    border-width:3px !important;
}

https://codeply.com/go/ktnEeWExvh

NOTE: !important is needed in this case because Bootstrap also uses !important in many of the utility classes like border-*.